# STEREO/IMPACT/SEP Operations Manual

# for the

# High Energy Telescope (HET)

# and 

# Suprathermal Ion Telescope (SIT)

# 

# Version 1.0 

# 10/11/06

##  

## Contributions by: 

Glenn Mason

> Tom Nolan

Don Reames

> Larry Ryan
>
> Peter Walpole
>
> Kristin Wortman
>
> Tycho von Rosenvinge

##  Compiled by: 

> Kristin Wortman

# 1.0 Background

The STEREO/IMPACT/ HET and SIT flight software was designed to run on a
CPU24 processor. The HET interfaces with its front-end electronics and
the SEP Central MISC through a series of Universal Asynchronous
Receiver/Transmitters (UARTs).

## 1.1 System Overview

## 

The LET, HET and SIT sensors each require a dedicated microprocessor for
onboard data processing. The microprocessor used for LET shall be the
P24 MISC (Minimal Instruction Set Computer. The microprocessor used for
HET shall be the CPU24 (24-Bit Embedded Microprocessor), which is
described below and in Reference 3. Processed data from all of the
microprocessors associated with these three sensors shall be gathered by
the SEP Central MISC (P24 processor), and formatted for transmission to
the IMPACT DPU (per Reference 5). The SEPT sensor does not have a
dedicated microprocessor, and data from SEPT shall flow directly to the
SEP Central MISC. Some processing of SEPT data shall occur in the SEP
Central MISC before the data are formatted and transmitted to the IMPACT
DPU. Figure 1 shows a block diagram of the SEP Instrument Suite.

![](media/image1.png){width="5.9944444444444445in"
height="5.055555555555555in"}

**Figure 1: SEP Instrument Suite Block Diagram**

## 1.2 Boot ROM

The CPU24 contains 16 words of ROM that holds a small program to boot
over the serial link. After a reset, the CPU24 starts execution at
location 0 which is mapped to the internal ROM. The instruction at
location 0 performs a jump to location 20001 (hex) where the remainder
of the boot code is located. A fixed number of bytes are received over
the serial link. Every three bytes received are packed into a 24-bit
word, with the first byte going into the most significant slot and the
third byte going into the least significant slot. Words are stored
beginning at address 1 in SRAM. Execution begins at address 1 (in SRAM)
following the serial transmission.

***Telemetry mode.*** The telemetry mode is a single byte that
determines the settings of all five telemetry control parameters. A mode
switch is performed only on major frame boundaries. When a new mode is
commanded, the telemetry control parameters are copied from a set of
hard-coded values associated with the mode. The hard-coded values
associated with each mode are set forth in the following table.

  ------- ---------- --------- --------- ------------ -----------------------
  Mode    Minor      Pkts per  Pkts per  Defined      Description
          Frame      Minor     Major     Packet       
          Interval   Frame     Frame     Sequence -   
                                         HET          

  0       3          1         8         G, F, A, B,  Flight telemetry
                                         C, C, C, D   

  3       3          1         8         A, B, G, F   Diagnostic flight mode
                                         and Raw      
                                         Event (ApId  
                                         597d)        
  ------- ---------- --------- --------- ------------ -----------------------

## 1.3 Document Referenced

-   *Description of the Suprathermal-Ion-Telescope*, Glenn Mason APL

-   *HET Telemetry Formatting*, Don Reames*,* Kristin Wortman

-   *STEREO/IMPACT/SEP HET and SIT Flight Software,* Tom Nolan, Kristin
    Wortman

-   *SIT Comprehensive Performance Test,* Peter Walpole

-   *HET Comprehensive Performance Test*, Larry Ryan*,,* Tycho von
    Rosenvinge, Kristin Wortman

-   *SIT HVPS In-flight Turn-on Procedure,* Glenn Mason, Peter Walpole,
    Kristin Wortman

# Instrument Commanding 

Commands are received from SEP Central over the bi-directional serial
port. The transmission scheme is asynchronous, character-by-character.
The baud rate is 57600. After the transmission of a command string is
complete, SEP Central listens. This is the window in which HET/SIT must
transmit a response, which is a printable ASCII string. After the
response, the flight instrument issues its prompt (either "HET\> " or
"SIT\> "). Commands may be received at any time, but they are executed
only on major frame boundaries.

The flight software maintains a circular queue of incoming characters.
The arrival of a character on the bi-directional serial port triggers
the highest-priority interrupt in the flight processor. The interrupt
service routine simply reads the character from the serial port and
writes it to the queue. No interpretation is done at this stage. The
queue can hold 2048 characters.

The background routine regularly checks the incoming character queue.
When a character is present, it is dequeued and passed to a finite-state
machine. The task of the finite-state machine is to recognize complete
commands, issue a response to SEP Central, and place completed commands
in another queue for execution at the next major frame.

Note that the command keywords "HETCMD" and "HETBINARY" which precede
any sequence of commands routed through SEP Central are interpreted by
SEP Central and not passed through to the instrument. (In order to
maintain compatibility during instrument testing, these commands
actually are recognized by HET and treated as a no-op, with no echo.)

## 2.1 ASCII Command Processing

Except for binary commands (described below), all commands are in
printable ASCII. They may be terminated by either a carriage return (13)
or a newline (10). The command state machine recognizes a complete
command when one of these two characters is received. It then performs
command preprocessing. The command preprocessor takes the following
steps:

-   If the command string is empty (only a carriage return or newline
    received), then the instrument prompt is sent.

-   If the command is one that requires immediate execution, it is
    dispatched to the command handler. Immediate execution commands are
    peekw, immed, and dump.

-   If the command string starts with a valid command keyword, then it
    is queued for later execution, and a command echo is sent, followed
    by the instrument prompt.

-   If none of the above is true, an error message is sent and prompt is
    sent.

For valid commands, the command echo consists of a 4-digit identifier
number (in hex) followed by a copy of the command string. The first two
digits of the identifier number are the least-significant byte of the
current major frame number, and the second two digits are the command
sequence number that is reset to zero in each major frame. After the
identifier, the command string is echoed as it was received. The
"cmdstr" command has a special echo to avoid repeating the entire
108-character string.

In immediate execution mode (immed 1), commands are queued for
processing, but they are pulled off the queue and executed immediately
instead of waiting for a major frame. The command echo contains an
asterisk inserted between the identifier number and the command echo.
This asterisk serves as a reminder that the command is executed
immediately instead of delayed until major frame time.

When a command does not begin with a recognized keyword, an error
message is sent, consisting of the received command followed by a
question mark. No identification number is sent in this case.

The final portion of the command echo is the instrument prompt, which is
sent in all cases (delayed command, immediate command, or error).

## 2.2 Binary Command Processing

A binary command consists of an ASCII introducer followed by a binary
load package. The introducer is the ASCII command keyword "binary." This
introducer is followed by a carriage return or line feed, just like an
ASCII command. Binary commands do not go through the preprocessing
described above. Instead, when the state machine recognizes the binary
introducer keyword, it prepares to receive a binary load package.

The binary load package contains a two-byte length, which is the number
of bytes to follow (including checksum), then the command bytes
themselves, then a two-byte checksum. Two-byte numbers are transmitted
most-significant byte first. The checksum is the 16-bit sum of all of
the 8-bit command bytes. The following table depicts the binary load
package format.

  ----------------- -----------------------------------------------------
  0                 Length msb

  1                 Length lsb

  2, . . ., N-1     N-2 command bytes, where N = Length

  N                 Checksum msb

  N+1               Checksum lsb
  ----------------- -----------------------------------------------------

When the finite-state machine recognizes the "binary" command
introducer, it does not dispatch it to the command preprocessor as it
would for an ASCII command. Instead, it enters a series of states to
receive the length, the command bytes, and the checksum. The binary
command load is placed in a large memory buffer (the binary command load
staging area).

When the two-byte checksum is received, the binary command payload is
finished. An echo is sent in one of the following two forms:

binary A:aaaaaaaa N:nnnnnnnn OK

or

binary A:aaaaaaaa N:nnnnnnnn ckserr cccccccc dddddddd

If the computed checksum matches the received checksum, the OK echo is
sent. The number following the "A:" is the relative address (i.e., the
byte number within the command load staging area where the binary
command payload was placed), and the number following the "N:" is the
number of bytes in the command payload. If the checksums do not match,
then the ckserr echo is sent, followed by the received checksum and then
the computed checksum.

A complete binary command load ordinarily consists of one or more
"binary" commands with binary payloads, followed by a single ASCII
"load" command. The "load" command instructs the flight instrument to
copy the binary load from the command load staging area to a specific
address in memory, which is the absolute address of the table or memory
area that is the ultimate destination of the command load (its target
address). When large tables are uploaded, multiple "binary" commands are
generally sent before the "load" is issued. The data in each binary
command payload is copied to consecutive locations in the command load
staging area. The command echo verifies that this is the case: in each
successive echo the address will be incremented by the length of the
previous load.

When a command load checksum fails, the relative address for the next
load package is still incremented as though the load package were
received correctly. This is done so that a large number of command loads
may be transmitted, the resulting command echoes examined, and only
those loads that were not received correctly may be retransmitted. The
retransmission of a failed command packet must be preceded by a "loadat"
command. The "loadat" command allows the specification of the relative
address for the retransmitted command load (which can be extracted from
the command echo corresponding to the failed command load).

The "load" command has three options. Load type zero (24-bit words)
packs three bytes into each word at the target address. Bytes are packed
msb, middle, lsb. The length of the table that is actually loaded at the
target address is n/3, where n is the number of binary command bytes
sent during the preceding binary commands. Load type 1 (1 byte per word)
copies one byte per word to the target address. The two most-significant
bytes of each target word are set to zero. Load type 2 (2 bytes per
word) packs two bytes into each word at the target address. Bytes are
packed msb, lsb (the most-significant byte of each 24-bit word at the
target address is set to zero). The length of the table that is actually
loaded at the target address is n/3, where n is the number of binary
command bytes sent. The load type 1 and 2 options afford some measure of
compression, because data stored at three bytes per word can be expanded
to either one or two bytes per word as appropriate.

For the "load" command, the number of bytes transferred to the target
address is determined by the preceding binary command sequence. All
bytes sent and received during the immediately preceding binary command
load sequence (which may consist of one or more individual command
loads) are copied into the target load address using the specified load
method. If the number of bytes is insufficient to fill out the last
target word (for example, if an odd number of bytes were received and
the load method is two bytes per word), the last word in the target area
will have zeroes in the extra byte positions. The "loadn" command
accepts an additional parameter -- the number of bytes to transfer --
and otherwise operates just like the "load" command. (If the byte count
on the "loadn" command exceeds the number of uploaded bytes, the
remainder will be undefined.)

After a "load" or "loadn" command, the flight software resets the
relative address within the binary command staging area to zero in
preparation for the next command load. When a "load" command is sent
with a target address of zero, the command has the effect of forcing the
relative address to zero, but no data are transferred. It would be good
practice to issue a "load 0" command before beginning any binary load
sequence because the "binary" commands rely on the flight software's
internal pointer mechanism.

The following command sequence illustrates the concepts described above
to load a 1024-word table, where each word is 3 bytes.

  ---------------- ----------------------- -------------------------------
  **Command**      **Response**            **Comments**

  load 0           0100 load 0             Reset load address, prepare for
                                           binary load

  binary                                   ASCII command, followed by CR
                                           or NL

  \[length=1026,   Binary A:000000         Binary payload, length includes
  1024 data bytes, N:000400 OK             2 checksum bytes
  checksum\]                               

  binary                                   ASCII command

  \[length=1026,   Binary A:000400         Second portion of binary
  1024 data bytes, N:000400 OK             payload
  checksum\]                               

  binary                                   ASCII command

  \[length=1026,   Binary A:000800         Third portion of binary payload
  1024 data bytes, N:000400 OK             
  checksum\]                               

  load 7000 0      0101 load 7000 0        Transfer binary command load to
                                           absolute address 7000 (hex), 3
                                           bytes per word at major frame 2
  ---------------- ----------------------- -------------------------------

### 

The following table shows the addresses where the HET tables will be
loaded in RAM:

  ------------- ------------ ---------------------------------------------
  **HET Table   **Length     **Description**
  Address       (hex)**      
  (hex)**                    

  18000         4000         Software counters (128 x 128)

  1C000         1000         Particle type (64 x 64)

  1D000         20           Addrtab (16x2)

  1D020         10           Offsetch (8 x 2)

  1D030         10           C-Delta E-Log GnFctr (8 x 2)

  1D040         10           gfctrnum (8 x 2)

  1D050         2            C-Resid E-Log H2 GnFctr (2)

  1D052         200          C-Delta E-Log 2

  1D252         200          C-Resid E-Log 2
  ------------- ------------ ---------------------------------------------

The following table shows the addresses where the SIT tables will be
loaded in RAM:

  ------------- ------------ ---------------------------------------------
  **SIT Table   **Length     **Description**
  Address       (hex)**      
  (hex)**                    

  7000          800          SSDHI

  7800          800          SSDLO

  8000          4000         BOX_ARRAY

  C000          200          TOFTAB
  ------------- ------------ ---------------------------------------------

### 2.2.1 Table Upload File Format for HET and SIT

For convenience, consistency, portability, and a host of other good
reasons, a file format was developed to permit the contents of HET table
uploads to be specified, edited, and packaged into binary commands for
transmission to the spacecraft or instrument. The flight software does
not read or interact directly with table upload files in this format.
Instead, routines for reading the files are included in the instrument
ground support systems. Using these routines, the ground support systems
read the table upload files and create binary commands in the format
described above, plus applicable headers. After mission-level,
spacecraft-level, and SEP Central processing, the binary commands reach
the flight software where they are interpreted and processed as
described above to load the table contents into memory.

A table upload file is a readable ASCII file consisting of four kinds of
lines: *introducers*, *addresses*, *table contents*, and *comments*.
They are described below.

An *introducer* line consists of the word "HETBINARY" or "SITBINARY" on
a line by itself, with no spaces or other characters before or after it.
The purpose of having two different introducers is so that tables cannot
be uploaded to the wrong instrument inadvertently.

An *address* line follows immediately after an introducer. It contains
three numbers, separated by spaces. The format for numbers obeys C
conventions. That is, each number is assumed to be decimal, unless it
begins with "0x," in which case it is assumed to be hexadecimal. The
first number is the address at which the table is to be loaded. This
address is an absolute address in the flight software address space. The
addresses of the major tables in the SIT and HET flight software are
found in the discussion above. The second number is the number of table
entries to follow. This normally corresponds to the size of the table.
The third number is the load type, which can be 0, 1, or 2. Load type 0
treats each table entry as a 24-bit word. All three bytes of each word
are transmitted to the flight software, then recombined into words and
stored at successive address locations. Load type 1 treats each table
entry as an 8-bit value. Only a single byte is transmitted to the flight
software, which stores successive bytes at successive address locations,
filling the most-significant 16 bits of each word with zeros. If the
table entry in the file is larger than can fit in one byte, it is
truncated to 8 bits. Load type 2 treats each table entry as a 16-bit
value. Two bytes are transmitted to the flight software, which combines
the two bytes into a 16-bit word, storing successive words at successive
address locations, filling the most-significant 8 bits of each word with
zeros. The reason for having load types 1 and 2 is to conserve
transmission bandwidth and load time when table entries are naturally
limited in extent.

A *table contents* line consists of one or more numbers separated by
commas, spaces, or tabs. There must be the same number of table entries
following the address line as specified in the second number of the
address line (i.e., the table size). However, the table entries can be
spread out over any number of lines. For example, each table entry could
appear on a separate line, or all the table entries could appear on the
same line (but lines are limited to 512 characters in total length). As
before, number formats obey C conventions. They must begin with a digit,
a minus sign, or a "0x." Any other character appearing where a number
ought to be ends that line (effectively acting as an inline comment).

A *comment line* is any line whose first character (other than spaces,
tabs, or commas) is not a digit or a minus sign. Comment lines can
appear anywhere in the table upload file except between an introducer
and the following address line. The comment line immediately preceding
the introducer is special -- it is a shorthand description of the table
that can be used by the upload software to inform the user of the table
that is about to be uploaded. Other comment lines appearing before the
introducer are ignored, and any comment lines appearing in the table
contents area are skipped until a line beginning with a numeric value is
found.

Multiple table uploads can appear in one file. Each table upload begins
with an introducer and address line, and is followed by sufficient table
contents lines to fill up the table. Following the table contents (and
any optional comments), another introducer may begin a second table
upload, and so on.

An example follows.

  -----------------------------------------------------------------------
  This table upload file contains two uploads.

  First is a sample table containing 13 entries, where each entry is no
  larger than 16 bits.

  HETBINARY

  0x1f000 13 2

  0, 10, 20, 50, 100, 200, 500, 1000 first 8 entries

  2000, 5000, 10000, 20000, 50000 next 5 entries

  Second is a sample table containing 4 entries, 24 bits each

  HETBINARY

  0x1f020 4 0

  -1

  -1

  0x55aa55

  -1
  -----------------------------------------------------------------------

## 2.3 HET Command Descriptions

**2.3.1 HET Commands**

This section lists the HET common commands, the instrument-specific
commands, and the table load addresses. All commands are case-sensitive.
All numeric arguments must be supplied in hexadecimal. A missing
argument or a non-numeric argument will be interpreted as the number
zero.

  -------------------- --------------------------------------------------
  **Command**          **Description**

  tmode N              Set telemetry mode. N=0...5. See description above
                       under Telemetry System.

  modw A N             Modify word at address A to value N.

  peekw A              Examine word at address A.

  binary               Receive binary command load package. Note that
                       this command is generated automatically by SEP
                       Central when a HET-BINARY package is received.

  immed N              Immediate command execution mode on (1) or off
                       (0). Default for flight: immed off (0).

  gwrite R N           Write value N to G-bus register R. \[THIS MAY
                       DISAPPEAR\]

  load A T             Transfer binary command load to address A using
                       load method T (0=W24, 1=B, 2=W16). The number of
                       bytes transferred is equal to the maximum relative
                       address written since the last load or loadn
                       command. This command is always executed
                       immediately, and not delayed until the next major
                       frame. The "dload" version of this command is to
                       be used for delayed execution.

  Dload A T            Same as load, except execution of the command is
                       delayed until the next major frame. The "dload"
                       version should be used to replace a table while
                       the instrument is operational, to avoid corrupted
                       major frames processed partially with the new
                       table. The "load" version should be used for
                       initial table loads to avoid overrunning the table
                       buffer.

  Loadn N A T          Transfer N bytes from binary command load staging
                       area to address A using load method T (0=W24, 1=B,
                       2=W16).

  loadat A             Set relative address to A for next binary command
                       load. A is a byte number starting from zero within
                       the current table.

  Cgate N              Turn clock gating on (1) or off (0).
  -------------------- --------------------------------------------------

**2.3.2 HET PHASIC Chip Command Descriptions**

There are two PHASIC chips in each HET flight unit, PHASIC 0 and
PHASIC 1. Both H1 detectors reside on PHASIC 0 and H2-H6 resides on
PHASIC 1. The channel settings used for each PHASIC chip is specific to
the flight model and are described in the table below.

**PHASIC Channel Configuration on HET Flight Boards**

  -------------- -------------- -------------- -------------- --------------
                 **Flight Model                **Flight Model 
                 1**                           2**            

  **Detector**   **PHASIC**     **Channel**    **PHASIC**     **Channel**

  H1i            0              1              0              1

  H1o            0              11             0              10

  H2             1              3              1              2

  H3             1              5              1              5

  H4             1              7              1              7

  H5             1              9              1              10

  H6             1              12             1              13
  -------------- -------------- -------------- -------------- --------------

The following HET commands configure the PHASIC chip registers, the
onboard stimulus pulser, and the DAC settings.

  --------------- -------------------------------------------------------
  **HET Command** **Description**

  cmdstr N S      Command PHASIC N to string S. N=0, 1. S is 108 hex
                  bytes long, representing left-justified 846-bit bit
                  string.

  dump N          Return contents of PHASIC N.

  testp P A B     Write 14-bit period, 9-bit DAC A and 9-bit DAC B values
                  to test pulser registers. The 9^th^ bit of each DAC
                  value is written to the respective DAC range bit. This
                  command stops the automatic background test pulser
                  algorithm. To resume automatic test pulser control, use
                  "testp auto" command.

  testp auto      Begin automatic background test pulser control
                  algorithm (default). This command is used after a
                  "testp" command has been sent to set manual values.

  scopesel N V    Write 9-bit value V to scope select bits, PHASIC N

  presel N V      Write 5-bit value V to preamp output mux select bits,
                  PHASIC N

  tpfbsel N P V   Test enable, test select, feedback select, PHASIC N
                  (0-1), PHA P(0-15), value V (9 bits)

  inresel N P V   Input resistor, input dac, PHASIC N (0-1), PHA P(0-15),
                  value V (16 bits)

  hgthrsel N P V  High gain threshold, PHASIC N (0-1), PHA P(0-15), value
                  V (10 bits)

  lgthrsel N P V  Low gain threshold, PHASIC N (0-1), PHA P(0-15), value
                  V (10 bits)

  phacont N P V   PHA control, PHASIC N (0-1), PHA P(0-15), value V (4
                  bits)

  lgorsel N X V   rndn-gor-X L enable, X=0,1,2, PHASIC N (0-1), value V
                  (16 bits)

  hgorsel N X V   rndn-gor-X H enable, X=0,1,2 PHASIC N (0-1), value V
                  (16 bits)

  setdac V        Set housekeeping dac to value V

  simevent N      Inject N simulated events into processing system. Event
                  values are taken from loadable table. If table ends
                  with --1, events are repeated until count expires.
                  Issue "simevent 0" to resume normal external event
                  processing.
  --------------- -------------------------------------------------------

The following tables depict the commonly used PHASIC commands and the
default boot flight configurations for all channels.

  ------------- -------- ----------- --------- -------- ------------------ ----------------
  **Command**   **PHA    **PHA       **Hex     **\# of  **Description**    **Default in HET
                chip**   channel**   bytes**   bits**                      initial command
                                                                           string**

  phacont       0-1      0-F         x         4        hg-adc-en,         Channels in use
                                                        lg-adc-en,         set to d, all
                                                        verbose, power-on  unused channels
                                                                           set to 0

  tpfbsel       0-1      0-F         xxx       9        test-enable,       H1i, H1o, H2, H6
                                                        testsel3,2,1,0,    set to 6; H3,
                                                        fbsel3,2,1,0       H4, H5 set to C

  inresel       0-1      0-F         xxxx      13       fdgsel2,1,0,       H1i, Hio, H2, H6
                                                        indac9,...,0       set to 1c30; H3,
                                                                           H4, H5 set to
                                                                           1c60

  hgthrsel      0-1      0-F         xxx       10       ioff9,...,0 (for   All channels set
                                                        high gain channel) to provide
                                                                           lowest possible
                                                                           threshold

  lgthrsel      0-1      0-F         xxx       10       ioff9,...,0 (for   All channels set
                                                        low gain channel)  to provide
                                                                           lowest possible
                                                                           threshold

  scopesel      0-1                  xxx       9        scopesel7,...,0,   000
                                                        scope-enable       

  presel        0-1                  xx        5        presel3,2,1,0,     00
                                                        preout-enable      
  ------------- -------- ----------- --------- -------- ------------------ ----------------

'**[phacont' Command]{.underline}**

The 'phacont' command is used like this:

phacont x y z

x = PHASIC \# (0 or 1)

y = channel \# (0 to F)

z = see table below for most common values to use

  ------- ------------------------------------------------------------------
  **z**   **Description**

  0       Turn off channel completely

  1       Disable HG and LG ADC's, but leave channel turned on

  7       Disable HG ADC, enable LG adc

  b       Enable HG ADC, disable LG adc

  d       Enable HG and LG ADCs, verbose mode off (default at boot-up)

  f       Enable HG and LG ADCs, verbose mode on
  ------- ------------------------------------------------------------------

**['tpfbsel' Command]{.underline}**

The 'tpfbsel' command is used like this:

tpfbsel x y z

x = PHASIC \# (0 or 1)

y = channel \# (0 to F)

z = see table below for most common values to use

  ------- ----------------------------------------------------------------
  **z**   **Description**

  6       Disable test pulser, set feedback capacitor to 30pF, and set
          test input capacitor to 0pF (default at boot-up for H1i, H1o,
          H2, H6)

  c       Disable test pulser, set feedback capacitor to 60pF, and set
          test input capacitor to 0pF (default at boot-up for H3, H4, H5)

  166     Enable test pulser, set feedback capacitor to 30pF, and set test
          input capacitor to 18pF

  1cc     Enable test pulser, set feedback capacitor to 60pF, and set test
          input capacitor to 36pF
  ------- ----------------------------------------------------------------

Note that currently the software boots up with the test pulsers disabled
and the test input capacitors set to 0. For flight, you will want the
test pulsers enabled and the test input capacitors set to the same
***hex*** setting as the feedback capacitors (6 for H1i, H1o, H2, H6; c
for H3, H4, H5). Using the same ***hex*** setting for feedback and test
input capacitors allows the test pulser DAC to probe the full dynamic
range of the HG and LG channels. More on that below in the description
of the 'testp' command.

**['inresel' Command]{.underline}**

The 'inresel' command should generally not be used, since the software
automatically sets the indac values (input current DAC to balance
detector leakage current).

**['hgthrsel' and 'lgthrsel' Commands]{.underline}**

These commands will generally not be used, since the thresholds have
been set. The current threshold values are programmed into the software
and will display on the housekeeping page. They should only be changed
(increased) if the noise goes up.

**['scopesel' and 'presel' Commands]{.underline}**

These commands are only useful on the Engineering Model now, and they
are described in Rick Cook's PHASIC document.

**['testp' Command]{.underline}**

The 'testp' command is used to run the on-board test pulser, and its
format is as follows:

testp x y z

x sets the test pulser frequency: freq = 1 / ( x/12500 + 1e-5 ) pulses
per second

(the default at boot-up is currently 4e2 = 10 pulses per second)

y sets the DAC setting for PHA #0 (common test input to H1i and H1o)

z sets the DAC setting for PHA #1 (common test intput to H2, H3, H4, H5,
H6)

(the defaults at boot-up for y and z are 0)

The DAC settings (y and z) can be as follows:

00 to ff (DAC voltages = 0V to .25V)

100 to 1ff (DAC voltages = 0V to 5.00V)

If the test input capacitor and feedback capacitor are set to the same
***hex*** setting (as described above in the 'tpfbsel' command section),
the low range of DAC voltages will stimulate the entire HG channel, and
the high range of DAC voltages will stimulate the entire LG channel.

The test pulser can be run in automatic mode, using this command: testp
auto

This will step through each of the DAC settings (one step per minute) at
the last selected pulser frequency.

## 2.4 Software Status Indicators

The flight software maintains a number of counters, status flags, error
indicators, and parameters as part of its operation. Certain of these
values are placed in the telemetry in each major frame as a check on
flight software operation. The tables below list each of the software
telemetry points for HET and SIT.

+-------------+-------------+------------------------------------------+
| **HET       | *           | **Description**                          |
| Variable**  | *Location** |                                          |
+-------------+-------------+------------------------------------------+
| Coi         | Pkt 590,    | Counts every event interrupt except      |
| ncidenceCnt | bytes 20-21 | stop_ev (g@8 bit 0 is set) and no_event  |
|             |             | (g@9 bit 8 is set). Cleared every        |
|             |             | minute.                                  |
+-------------+-------------+------------------------------------------+
| lastcmd     | Pkt 590,    | Highest command sequence number reached  |
|             | byte 44     | in major frame (equal to number of       |
|             |             | commands received that pass parsing).    |
|             |             | Resets from zero every minute.           |
+-------------+-------------+------------------------------------------+
| CmdErrBits  | Pkt 591,    | Bit set when command parsed correctly    |
|             | bytes 46-47 | but did not execute. Bit number          |
|             |             | corresponds to sequence number           |
|             |             | associated with command when received    |
|             |             | during previous major frame. Whenever    |
|             |             | any bit is set in this word, there will  |
|             |             | also be a software error flag set in bit |
|             |             | 6 of Errflags (see below).               |
+-------------+-------------+------------------------------------------+
| IdleCnt     | Pkt 591,    | Counts every pass through the background |
|             | bytes 48-49 | loop, read out and cleared every minute. |
|             |             | Provides a "livetime" check, since more  |
|             |             | time spent in interrupt and event        |
|             |             | processing will decrease this count. For |
|             |             | this check to work, clock gating needs   |
|             |             | to be off (cgate 0).                     |
+-------------+-------------+------------------------------------------+
| Errflags    | Pkt 598,    | Bit set corresponds to an error          |
|             | bytes 29-30 | encountered during previous major frame  |
|             |             | time. Cleared every minute.              |
|             |             |                                          |
|             |             | Bit 0: Receive queue full                |
|             |             |                                          |
|             |             | Bit 1: Transmit queue full               |
|             |             |                                          |
|             |             | Bit 2: Command queue full                |
|             |             |                                          |
|             |             | Bit 3: Command buffer overflow           |
|             |             |                                          |
|             |             | Bit 4: Command handler timeout           |
|             |             |                                          |
|             |             | Bit 5: Command syntax error (command     |
|             |             | rejected)                                |
|             |             |                                          |
|             |             | Bit 6: Command processing error          |
|             |             | (CmdErrBit set)                          |
|             |             |                                          |
|             |             | Bit 7: Callback timer error              |
|             |             |                                          |
|             |             | Bit 8: ADC timed out                     |
|             |             |                                          |
|             |             | Bit 9: Queuing error, queue reset to     |
|             |             | empty state                              |
+-------------+-------------+------------------------------------------+
| swVer       | Pkt 598,    | Software version tag. LSB (byte 31) is   |
|             | bytes 31-32 | day of month, MSB (byte 32) is month in  |
|             |             | which version was created.               |
+-------------+-------------+------------------------------------------+
| Err_event   | Pkt 598,    | Event read from hardware but no token    |
|             | bytes 33-34 | bit was set. Event was counted in        |
|             |             | CoincidenceCnt but not processed.        |
+-------------+-------------+------------------------------------------+
| No_event    | Pkt 598,    | Event interrupt handled but no_event bit |
|             | bytes 35-36 | was set to 1 (g@9 bit 8). Event not      |
|             |             | counted in CoincidenceCnt.               |
+-------------+-------------+------------------------------------------+
| Lost_event  | Pkt 598,    | Event could not fit in raw event queue.  |
|             | bytes 37-38 | The raw event queue is only used in      |
|             |             | laboratory testing. Data in raw event    |
|             |             | queue is used to fill packet 598. If     |
|             |             | this counter still exists in the flight  |
|             |             | version, it will increment at high data  |
|             |             | rates because the raw event queue is     |
|             |             | never emptied. However, it is not an     |
|             |             | error and the events are also processed  |
|             |             | normally.                                |
+-------------+-------------+------------------------------------------+
| t           | Pkt 598,    | Major frame number. This is necessary in |
| mMajorFrame | bytes 39-40 | order to correlate housekeeping packets  |
|             |             | with science packets. Each science       |
|             |             | packet has the major frame number in the |
|             |             | HET header following the CCSDS header.   |
|             |             | The housekeeping packet is merged into   |
|             |             | the SEP Central housekeeping and does    |
|             |             | not have a HET header.                   |
+-------------+-------------+------------------------------------------+
| ch          | Pkt 598,    | Three-byte checksum of entire table      |
| ecksum_csum | bytes 41-43 | area. The table checksum is computed on  |
|             |             | the ground during the flight software    |
|             |             | build process, and should match this     |
|             |             | computed checksum. The checksum is       |
|             |             | computed one word at a time in the       |
|             |             | background idle loop. This may take some |
|             |             | time if clock gating is enabled (cgate   |
|             |             | 1). Table entries are added using a      |
|             |             | 24-bit sum, ignoring carries. Once the   |
|             |             | entire table area has been added up, the |
|             |             | result is telemetered and the            |
|             |             | calculation is repeated.                 |
+-------------+-------------+------------------------------------------+

## 2.5 SIT Command Descriptions

The following commands are passed on to the front end logic:

### 2.5.1 One-Bit Commands 

The following commands consist of a single bit each and control a single
function in the front-end logic.

-   **hvenable** - enables the high voltage power supply

> 1=enable, 0 = disable, turn-on state = 0,
>
> Expected use: sent every time instrument is turned on to NORMAL (or
> Science) mode.

-   **eonly** - allows analysis of events based on energy without the
    TOF

> 1 = EONLY, 0 = normal mode, turn-on state = 0
>
> Expected use - diagnostic or in case of failure of TOF system

**2.5.2 Data Commands (8 bits)**

The following commands contain 8 bits of data each and control an analog
function in the front-end electronics.

-   **hvlevel** - sets the top voltage out of the HVPS

values: 0-255, 0 = 0 volts, 255 = tbd (\~5000v), turn-on state = 0

> Expected use - several commands will be sent each time the instrument
> is turned on into NORMAL (or Science) mode to step the HV up to the
> correct operating level. In addition, on rare occasions (perhaps once
> per year) the HV will need to be changed to compensate for operational
> loss of gain in the micro-channel plates.

-   **threshold** - sets the SSD discriminator threshold

values: 0-255, 0 = low threshold, 255 = high threshold, turn-on state =
0

> Expected use - send once every time the instrument is turned on. On
> rare occasions it may be necessary to change the threshold to
> compensate for increased noise in the solid-state detector.

**2.5.3 Commands to the CPU24**

The following commands are processed within the CPU24, setting flags or
changing values in memory.

**2.5.3.1 State Command**

The following command sets the CPU24 operating mode

-   **toferror** - tells CPU24 whether to process events with TOF error
    bits set

1 = process events independent of TOF error bits

0 = only process events with TOF error flags = 0

turn-on state = 0

Expected usage - diagnostic and error recovery

2.  **Binary Commands**

Refer to section 2.2 for a description on the binary commands to change
the contents of CPU24 memory locations which store the SIT
event-processing look-up tables.

## SIT Command Summary

The following tables describe the format of the SIT commands.

  --------------------- -------------------------------------------------
  **SIT Command**       **Description**

  tmode N               Set telemetry mode. N=0...5. See telemetry mode
                        descriptions in section 1.2.

  modw A N              Modify word at address A to value N.

  peekw A               Examine word at address A.

  binary                Receive binary command load package. Note that
                        this command is generated automatically by SEP
                        Central when a SIT-BINARY package is received.

  immed N               Immediate command execution mode on (1) or off
                        (0). Default for flight: immed off (0).

  gwrite R N            Write value N to G-bus register R. \[THIS MAY
                        DISAPPEAR\]

  load A T              Transfer binary command load to address A using
                        load method T (0=W24, 1=B, 2=W16). The number of
                        bytes transferred is equal to the maximum
                        relative address written since the last load or
                        loadn command. This command is always executed
                        immediately, and not delayed until the next major
                        frame. The "dload" version of this command is to
                        be used for delayed execution.

  dload A T             Same as load, except execution of the command is
                        delayed until the next major frame. The "dload"
                        version should be used to replace a table while
                        the instrument is operational, to avoid corrupted
                        major frames processed partially with the new
                        table. The "load" version should be used for
                        initial table loads to avoid overrunning the
                        table buffer.

  loadn N A T           Transfer N bytes from binary command load staging
                        area to address A using load method T (0=W24,
                        1=B, 2=W16).

  loadat A              Set relative address to A for next binary command
                        load. A is a byte number starting from zero
                        within the current table.

  cgate N               Turn clock gating on (1) or off (0).
  --------------------- -------------------------------------------------

  ----------------- -----------------------------------------------------
  **SIT Command**   **Description**

  hvenable N        Enable high voltage (N=0,1)

  eonly N           Control eonly bit (N=0,1)

  hvlevel V         Set 8-bit HV level

  toferror N        TOF error events (N=0,1)

  limhi V           Set LIMHI to 8-bit value

  junk N            Store junk events (N=0,1)

  hvramp V          Ramps the HV up to the HV level
  ----------------- -----------------------------------------------------

## 

## 2.7 Diagnostics

The software error flags are accumulated during each major frame, i.e.,
every occurrence of an error causes the corresponding bit to be or'ed in
to the error flags word. At the end of the major frame the bits are read
out into the housekeeping telemetry and cleared. The bit definitions for
software error flags are described in the following table.

  ------------- ---------------------------------------------------------
  Bit           Definition (bit = 1)

  0             Receive character queue overflow

  1             Transmit character queue overflow

  2             Incoming command queue overflow

  3             Buffer overflow in command preprocessing

  4             Command handler timeout

  5             Command syntax error

  6             Command processing error

  7             ADC callback timer error

  8             ADC timeout in phasic baseline
  ------------- ---------------------------------------------------------

# 

# 3.0 Telemetry Packet Formats

## 3.1 HET Telemetry Packet Formats

All rates in the SIT packets are log compressed from 24-bit to 16-bit
quantities for telemetry according to the algorithm given in section
3.4.6.

The following table provides the Application Identifiers (ApId) that
appear in the CCSDS header to identify HET science packets.

  ----------------------------------- -----------------------------------
  **APID**                            **Description**

  590 (Hex 24E)                       Singles RATE

  591 (Hex 24F)                       Status and Single PHA

  592 (Hex 250)                       Stopping Particle PHA

  593 (Hex 251)                       Penetrating Particle PHA

  594 (Hex 252)                       Table Listing

  595-596 (Hex 253-254)               Not Used

  597 (Hex (255)                      Tmode=3 Raw Events

  598 (Hex 256)                       Housekeeping

  599 (Hex 257)                       Beacon
  ----------------------------------- -----------------------------------

The telemetry output of the STEREO IMPACT HET telescope contains CCSDS
packets in 7 different data formats:

A.  Rate packets

B.  Status and single PH packets

C.  Stopping particle PH packets

D.  Penetrating particle PH packets

E.  Table status dump

F.  Beacon packets

G.  Housekeeping data packets

After individual particle pulse height (PH) events are recorded by HET,
the onboard processing algorithm identifies particle species and
energies and bins the particles in "software rate counters," as
distinguished from hardware counters in the front-end electronics. The
identification of these counters is given in Appendix A. In addition to
binning all the particles, samples of the raw PH events are selected in
8 categories (see Appendix B) for inclusion in the telemetry stream. The
format of the PH events themselves is given in B.2. Note that PH events
can vary in length from 2 to 16 bytes (always even). All rates are log
compressed from 24-bit to 16-bit quantities for telemetry according to
the algorithm given in Appendix C. Quantities longer than one byte are
written into the packets least-significant byte first.

The following sections describe the formats of individual packet types.
In normal operation, HET generates 6 primary packets during a one-minute
frame; these might be formatted as follows: 1 A, 1 B, 3 Cs and 1 Ds. E
packets are multiplexed out on at a rate that can be selected by
command. In flight, typically, E packets replace a PH packet once every
16 min to produce a complete dump every \~5 days. F and G packets
contribute the HET portions of the SEP beacon and housekeeping data.
Section 8 discusses an algorithm for selection of sample PHs to fill the
PH packets.

The CCSDS header format is defined in the STEREO MOC to POC Interface
Control Document.

### 3.1.2 'A' or Rate packets (ApID: 590 (dec) 24e (hex)): 

Rate packets are formatted as follows:

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       A-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         2           Livetime

  18         2           Trigger rate

  20         2           Coincidence rate

  22         2           Total number of events (excludes stimulus
                         events)

  24         2           N singles queued

  26         2           N stopping events queued

  28         2           N penetrating events queued

  30         2           N stopping H

  32         2           N stopping He

  34         2           N stopping heavies

  36         2           N penetrating H

  38         2           N penetrating He

  40         2           N penetrating heavies

  42         2           N invalid events -- out of sequence (reg and
                         stim events )

  44         2           N invalid events -- H1i & H1o, but not stimulus
                         events

  46         2           N invalid events -- inconsistent dE/dx (reg and
                         stim events)

  48         2           N invalid events -- H1 not first ph (reg and
                         stim events)

  50         2           N stimulus events (all types of stimulus events)

  52         12          6 background event bins 0-5

  64         150         75 stopping event bins 6-80

  214        16          8 penetrating event bins 81-88

  230        26          13 single event bins 89-101

  256        14          7 stimulus event bins 102-108

  270        1           TBD

  271        1           checksum
  ---------- ----------- ------------------------------------------------

### 3.1.3 'B' or Status and Single PH Packets (ApID: 591 (dec) 24f (hex)): 

B packets are somewhat of a catchall. They contain instrument status and
health bytes, H1 single PH events, stimulator (STIM) event PHs and a few
extra rates. They are formatted as follows:

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       B-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         28          14 Single detector rates

  44         1           number of commands received in previous major
                         frame

  45         1           zero

  46         2           command errors (bit N = 1 if command N had an
                         execution error, N=0-15)

  48         2           background idle counts (compressed)

  50         14          Offsets for current selected channels (h1i
                         logain=0, h1i logain=1, h1o logain=0, h1o
                         logain=1, h2 logain=0, h2 logain=1, h3 logain=0,
                         h3 logain=1\... h6 logain=0, h6 logain=1)

  64         7           h1i chip=0 addr, h1o chip=0 addr, h2 chip=1,
                         addr, h2 chip chip =1 addr..h6 chip=1 addr

  71         3           Status Bytes (TBD)

  74         100         50 sample H1-only PHs

  174        96          STIM PH events

  270        1           N stimulus events in packet

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

### 3.1.4 'C' or Stopping-Particle PH Packets (ApID: 592 (dec) 250 (hex)): 

C packets contain PH events for stopping particles. They are formatted
as follows:

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       C-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         2           N of stopping events

  18         252         Stopping event PHs

  270        1           TBD

  271        1           checksum
  ---------- ----------- ------------------------------------------------

Stopping particles produce PHs in from 2 to 5 detectors, so their
description contains from 6 to 12 bytes (appendix B). This means that a
packet can contains a maximum of 42 events, but contains at least 21
events if they are available. Since event lengths are variable, extra
space may exist at the end of the PH region that is too small for
another event. Any such bytes following the last PH event must be 0
filled.

### 3.1.5 'D' or Penetrating-Particle PH Packets (ApID: 593 (dec) 251 (hex)): 

D packets contain PH events for penetrating particles. They are
formatted as follows:

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       D-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         2           N of penetrating events

  18         252         0-18 Penetrating event PHs

  270        1           TBD

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

## Penetrating particles produce PHs in 6 detectors, so their description contains 14 bytes (appendix B). 

### 3.1.6 'E' or Table Listing Packets (ApID: 594 (dec) 252 (hex)): 

E packets contain a listing of a segment of the table and constant
region of the MISC-24 processor's memory. They are formatted as follows:

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       E-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         3           Beginning address

  19         252         Data

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

Generally, "Data" will consist of the next 84 24-bit words of memory
beyond the beginning address. These packets are designed to slowly
multiplex the contents of large sections of memory into the telemetry
stream. Typically, one E-packet will be written every 16 major frames
(minutes) in place of a PH packet.

### 3.1.7 'F' or Beacon Packets (ApID: 599 (dec) 257 (hex)

Beacon packets transmit HETs share of the SEP beacon packet.

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       F-packet contents

  0          11          CCSDS header

  2          2           Electrons 0.7-4 MeV - sum of sw bins 6-8

  4          2           Protons 13-21 MeV -- sum of sw bins 9-12

  6          2           Protons 21-40 MeV -- sum of sw bins 13-18

  8          2           Protons 40-100 MeV -- sum of sw bins 81-82

  10         2           He 13-21 MeV/n -- sum of sw bins 24-27

  12         2           He 21-40 MeV/n -- sum of sw bins 20-22

  14         2           He 40-100 MeV/n -- sum of sw bins 86-87

             2           C+O 30-52 MeV/n - sum of sw bins 35-39, 42-46

             2           C+O 52-74 MeV/n - sum of sw bins 40-41, 47-48

             2           Fe 52-74 MeV/n - sum of sw bins 73-74

             2           Livetime

             2           Stop. efficiency (TBD)

             2           Pen. efficiency (TBD)

             2           HET status (TBD)

  270        1           TBD

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

The rate quantities in the beacon data packet are derived by summing
software rates described in Appendix A. Regions in the packet other than
the header and defined HET data block are filled with 0.

### 3.1.8 'G' or Housekeeping Packets (ApID: 598 (dec) 256 (hex))

G packets contain the HET contribution to the housekeeping data packet.
Regions other than those defined are 0 filled.

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       G-packet contents

  0          11          CCSDS header

  11         1           ADC Temp 1

  12         1           ADC Temp 2

  13         1           PHASIC 0 PH channel ID

  14         1           PHASIC 0 ADC Preamp

  15         2           PHASIC 0 high gain threshold

  17         2           PHASIC 0 low gain threshold

  19         2           PHASIC 0 leakage current DAC setting

  21         1           PHASIC 1 PH channel ID

  22         1           PHASIC 1 ADC Preamp

  23         2           PHASIC 1 high gain threshold

  25         2           PHASIC 1 low gain threshold

  27         2           PHASIC 1 leakage current DAC setting

  29         2           Error Flags (16 bits)

  31         2           Software version ID (16 bits)

  23         2           N invalid token

  35         2           N invalid trigger

  37         2           N lost raw events

  39         2           Major frame number

  41         3           Table checksum

  44         1           24-bit DAC value, bits 0:7 (PHASIC 0 DAC)

  45         1           24-bit DAC value, bits 8:15 (PHASIC 1 DAC)

  46         1           24-bit DAC value, bits 16:23 (un:4, mux:2,
                         rng1:1, rng0:1)

  47         5           Available (TBD)

  52         219         Not available for use

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

### 3.1.9 Raw Event Packet (ApId: 597 (dec) 255 (hex))

This packet is a diagnostics packet and should not normally be generated
in flight mode.

The raw event packet is generated when the FSW has been configured to
tmode 3 when connected to SEP Central, and tmode 1 when not connected to
SEP Central. This packet replaces the packets with ApId 592 and 593 in
tmode 3, and is generated in addition to the other packets at every
unused second in tmode 1. This packet should generally be used when
analysis requires reviewing the raw (24 bit) events before particle
processing.

  ---------- ----------- ------------------------------------------------
  Offset     Bytes       597-packet contents

  0          11          CCSDS header

  11         1           HET mode byte

  12         2           TBD

  14         2           Major frame number

  16         255         85 24-bit raw events

  271        1           Checksum
  ---------- ----------- ------------------------------------------------

## 3.2 HET Pulse Height Event Selection

In large solar energetic-particle events, the number of particles
collected by HET will exceed by far the space available for PH events in
the PH packets. Since most of these particles are protons, intelligent
sampling is required to insure that other species are sampled. As a part
of the onboard processing and binning of each particle, sampled PH
events for stopping and penetrating particles are queued as protons,
helium, or heavy ions. Approximately 1/3 of the telemetry space will be
reserved for each species, but vacant space will be filled. That is, if
there are 3 C packets being sent per frame, one will be dedicated to
each species. However, if the "heavies" packet is not full, the space
will be filled by any left over He. Then, if the Heavy and He packets
have space, it will be filled with H PH events. A similar process will
be used to fill the 18 slots in the D packet with penetrating-ion events
(6 each).

If all stopping PH events fit in 3 C packets, all will be sent; if all
fit in 1 or 2 C packets only, those will be sent, leaving room for extra
D packets. In quiet times, 1 D packet should contain all Galactic Cosmic
Ray events, but additional D packets might be useful very early in a
large SEP event, before many stopping ions arrive. When all
pulse-heights fit in a 1 C packet and 1 D packet, 2 E packets may be
sent to fill the 6 packet/min frame. This is the minimum quiet-time set
of packets.

Note that the queues for the 8 categories of sample PH events (see B.1)
will have to be long enough to accommodate the maximum "backfill" of the
packets. For example the stopping proton queue must fill 3 C packets
(max. 126 events) in case there are no stopping He & heavies; He must
fill 2 C packets (max. 84 events), and heavies 1 (max 42 events).
Similarly, penetrating H events must fill as many as 3 D packets (54
events) and pen. He must fill 2 D packet (36 events) and heavies 1 (18
events). Note that only those PHs to be actually transmitted need to be
converted to compressed PH format.

Frame rates higher than one per minute may be required for accelerator
calibrations.

## 3.3 HET Onboard Software Count Bins

### 3.3.1 H1 Singles Events

H1 -- only events are mapped to MeV and binned in 2-MeV intervals out
just beyond the proton endpoint, and then 4-MeV intervals to beyond the
He endpoint. Intervals (18) are:

0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-20, 20-24, 24-28,
28-32, 32-36, 36-40, 40-44, 44-48, 48-52, \>52.

### 3.3.2 Stopping Particles

Identified species and energy intervals are shown:

  --------------- ------------- ----------- ------- ------- -------- -------- -------- --------
  **MeV/n**       **H&^4^He**   **^3^He**   **C**   **O**   **Ne**   **Mg**   **Si**   **Fe**

  **13-15**       X                                                                    

  **15-**         X                                                                    

  **17-**         X             17-21                                                  

  **19-**         X                                                                    

  **21-**         X             21-27                                                  

  **24-**         X                                                                    

  **27-**         X             27-33       x                                          

  **30-**         X                         x       x                                  

  **33-**         X             33-40       x       x       x                          

  **36-**         X                         x       x       x                          

  **40-**                       40-47       x       x       x        x        x        

  **45-**                                   x       x       x        x        x        

  **52-**                                   x       x       x        x        x        x

  **62-**                                   x       x       x        x        x        x

  **74-**                                           x       x        x        x        x

  **87-**                                                   x        x        x        x

  **98-**                                                            x        x        x

  **109-**                                                                    x        x

  **119-**                                                                             x

  **140-163**                                                                          x

  **Bin-Count**   20            5           8       8       8        7        8        8
  --------------- ------------- ----------- ------- ------- -------- -------- -------- --------

Total 72 bins for stopping ions, plus 3 background bins.

Electrons are accumulated in 3 bins: 0.7-1.4, 1.4-2.8, and 2.8-4.0 MeV

### 3.3.3 Penetrating Particles

Bins for penetrating particles are as follows:

  ------------------------------------------ ------------ ---------------
  **MeV/nucleon**                            **H**        **He**

  **40-60**                                  x            x

  **60-100**                                 x            x

  **100-200**                                x            x

  **200-400**                                x            

  **\>400**                                  x            

  **Bin-count**                              5            3
  ------------------------------------------ ------------ ---------------

There are a total of 8 bins for penetrating particles, plus 2 background
bins.

### 3.3.4 Pulse-Height Selection and Formatting

### 3.3.4.1 Pulse-Height Categories

In the process of the onboard identification and binning of particle
pulse-height (PH) events, sample events are selected and formatted for
telemetry. To prevent PH events of a given type (*e.g*. protons) from
dominating the telemetry stream, events are grouped in the following
categories:

> 0 - H1 singles
>
> 1 - Stopping protons

2 - Stopping He

3 - Stopping heavies

4 - Penetrating protons

5 - Penetrating He

6 - Penetrating heavies

7 - PH stimulator events

Singles events consist of a single PH in the H1 (H1i or H1i) detector.
Stopping events consist of PHs from 2 to 5 detectors, H1, H2, (...H5).
Penetrating events consist of 6 detectors H1 through H6. PH stimulator
events consist of up to 7 PHs: H1i, H1o, H2, ...H6. All events are
presumed to be valid events, in that the PHs are ordered consistently,
since invalid events (*e.g*. H1H2H5) have been weeded out early during
PH interrupt service. Each event has been tallied in an onboard particle
species and energy "software" bin, although that bin may be a
"background" bin between actual particle tracks.

Each event category is allocated a fixed basic amount of space in the
output data packets. This insures adequate representation of the
categories in a large solar particle event. However, if there are not
enough events in a given category to fill the allotted space at the end
of each one-minute "frame," events from another category are allowed to
occupy that space, in a priority order, until all available PH telemetry
space in the packets is filled or all events are telemetered. This means
that more PH events in each category should be queued than can fit in
the basic allocation for that category. Basic allocations and filling
priorities are presently TBD.

### 3.3.4.2 PH Event Format

With the exception of the H1 singles events, discussed below, all PH
events consist of a 16-bit header followed by the appropriate number of
16-bit packed pulse heights. The bit pattern of the 16-bit header is as
follows (listed in lsb to msb order):

3-bits Count of PHs in this event

8-bits Onboard SW bin this event was assigned to

1-bit Stimulator event flag

1-bit Current rate mode of the HET

3-bits PH category

Each individual PH is compressed from the 24-bit value read from the
ASIC to a 16-bit value with the following bit pattern (lsb to msb)

11-bits PH value

1-bit Overflow bit

1-bit High/low gain

3-bit PH number (H1i, H1o, H2, ...H6)

To save space, H1 singles are treated differently from other events in
that they have no header but consist only of a single 16-bit PH event as
defined above. Because of this, they occupy a fixed space in the
telemetry packets that cannot be shared with events in other PH
categories.

Note that stopping and penetrating events can be mixed arbitrarily.
Using the PH-counts in the PH-header it is possible to traverse
logically from event to event throughout a list of events.

In the process of storing PH events in a 272-byte packet buffer, one may
arrive at a place where an event is too large to fit in the remaining
space. In this case, the remaining space in the packet is zeroed and the
event is stored elsewhere or omitted. This will result in a PH-count of
0 when an attempt is made to read this event on the ground.

## 3.4 SIT Telemetry Packet Format Descriptions

All rates in the SIT packets are log compressed from 24-bit to 16-bit
quantities for telemetry according to the algorithm given in section
3.4.6.

The following table provides the Application Identifiers (ApId) that
appear in the CCSDS header to identify HET science packets.

  --------------------------------------- -------------------------------
  **SIT APID**                            **Description**

  605 (Hex 25D)                           RATE

  606 (Hex 25E)                           PHA packet #1

  607 (Hex 25F)                           PHA packet #2

  608 (Hex 260)                           PHA packet #3

  609 (Hex 261)                           PHA packet #4

  610 (Hex 262)                           PHA packet #5

  611 (Hex 263)                           PHA packet #6

  612 (Hex 264)                           PHA packet #7

  613 (Hex 265)                           PHA packet #8

  614 (Hex 266)                           PHA packet #9

  615 (Hex 267)                           PHA packet #10

  616 (Hex 268)                           PHA packet #11

  617 (Hex 269)                           Test mode=2 (raw events)

  618 (Hex 26A)                           Housekeeping

  619 (Hex 26B)                           Beacon Rates

  623 (Hex 26F)                           Fill
  --------------------------------------- -------------------------------

### 3.4.1 Rate Packet (ApID: 605)

> The rate packet contains discriminator and matrix rates, and command
> status information. There is no multiplexing.

+--------------------+-------------------------------------------------+
| **Byte \#**        | **Description**                                 |
+--------------------+-------------------------------------------------+
| 1-11               | CCSDS                                           |
+--------------------+-------------------------------------------------+
| 12-13              | Discriminator Rate (=DR) 1\-- START singles     |
+--------------------+-------------------------------------------------+
| 14-15              | DR2 -- STOP singles                             |
+--------------------+-------------------------------------------------+
| 16-17              | DR3 -- Valid Stop                               |
+--------------------+-------------------------------------------------+
| 18-19              | DR4 -- SSD singles                              |
+--------------------+-------------------------------------------------+
| 20-21              | DR5 -- Event (triple coincidence)               |
+--------------------+-------------------------------------------------+
| 22-23              | DR6 -- Dead time counter                        |
+--------------------+-------------------------------------------------+
| 24-25              | DR7 -- Artificial STOP count (TOF diagnostic)   |
+--------------------+-------------------------------------------------+
| 26-27              | DR8 -- TOF system error count                   |
+--------------------+-------------------------------------------------+
| 28-29              | Matrix Rate (=MR) MR1                           |
+--------------------+-------------------------------------------------+
| 30-31              | MR2                                             |
+--------------------+-------------------------------------------------+
| 32-33              | MR3                                             |
+--------------------+-------------------------------------------------+
| 34-35              | MR4                                             |
+--------------------+-------------------------------------------------+
| 36-37              | MR5                                             |
+--------------------+-------------------------------------------------+
| 38-259             | MR6 -- MR116                                    |
+--------------------+-------------------------------------------------+
| 260                | hvstep                                          |
+--------------------+-------------------------------------------------+
| 261                | 4 1-bit flags:                                  |
|                    |                                                 |
|                    | bit 0 (lsb): 0 = TOF error events transmitted   |
|                    |                                                 |
|                    | 0 = TOF error events dropped                    |
|                    |                                                 |
|                    | bit 1: 0 = HV disabled                          |
|                    |                                                 |
|                    | 1 = HV enabled                                  |
|                    |                                                 |
|                    | bit 2: 0 = VS required for analysis             |
|                    |                                                 |
|                    | 1 = SSD only required for analysis              |
|                    |                                                 |
|                    | bit 3: 0 = ROM box 0 events dropped             |
|                    |                                                 |
|                    | 1 = ROM box 0 events transmitted                |
+--------------------+-------------------------------------------------+
| 262-263            | LIMHI                                           |
+--------------------+-------------------------------------------------+
| 264-266            | 3-byte lookup table checksum                    |
+--------------------+-------------------------------------------------+
| 267-271            | spare                                           |
+--------------------+-------------------------------------------------+
| 272                | checksum                                        |
+--------------------+-------------------------------------------------+

### PHA Packets (ApIDs: 605-616)

  -------------------- --------------------------------------------------
  **Byte \#**          **Description**

  1-11                 CCSDS Header

  12-15                PHA event 1

  16-19                PHA event 2

  20-23                PHA event 3

  24-27                PHA event 4

  28-267               PHA event 5-64

  268-270              spare

  271                  Number of PHA events in packet

  272                  checksum
  -------------------- --------------------------------------------------

### PHA Raw Event Packet (ApID: 617)

  -------------------- --------------------------------------------------
  **Byte \#**          **Description**

  1-11                 CCSDS Header

  12-15                PHA event 1

  16-271               PHA event 2 - 65

  272                  checksum
  -------------------- --------------------------------------------------

### 3.4.4 Housekeeping Packet (ApId 618)

### 

  ---------------------- ------------------------------------------------
  **Byte \#**            **Description**

  1-11                   CCSDS Header

  12-13                  Major Frame \#

  14-15                  TOF gain Cal \* 2048

  16-17                  TOF Cal offset \* -64

  18                     TOF Cal error

  19                     HV monitor

  20                     TOF temp

  21                     SSD temp

  22                     foil temp

  23                     +3.3 V monitor

  24                     +2.4 V monitor

  25                     +5.0 Digital V monitor

  26                     +6.0 V monitor

  27-28                  Software version

  29-31                  lookup table checksum

  32-271                 unused

  272                    checksum
  ---------------------- ------------------------------------------------

### 3.4.5 Beacon Data Packet (ApId 619)

  ---------------------- ------------------------------------------------
  **Byte \#**            **Description**

  1-11                   CCSDS Header

  12-13                  Beacon Rate 1 (compressed)

  14-34                  Beacon Rate 2 -- 12 (compressed)

  35-271                 unused

  272                    checksum
  ---------------------- ------------------------------------------------

### 3.4.6 . Rate Compression Algorithm

/\* 32-bit (or 24-bit) -\> 16-bit compression for SW and HW rates \*/

/\* useage: rateout=pack_rate(ratein); \*/

unsigned int pack_rate(ratein)

long ratein;

{

unsigned int rateout, power=0;

while (ratein&0xfffff000)

{

power+=0x0800;

ratein\>\>=1;

}

rateout=ratein;

if (power)

rateout=power+0x0800\|((rateout&0x07ff));

return rateout;

}

/\* Unpacking (not required in flight code) \*/

long long_rate(packed) /\* Unpack to long \*/

unsigned packed;

{

int power;

long out;

power= packed\>\>11;

if (power\>1)

{

out=((packed&0x07ff)\|0x0800);

out=out\<\<(power-1);

}

else

out=packed;

return out;

}

double dbl_rate(packed) /\* Unpack to double \*/

unsigned packed;

{

int power;

double out;

power= packed\>\>11;

if (power\>1)

{

out=((packed&0x07ff)\|0x0800);

out=out\*pow(2.,(double)(power-1));

}

else

out=packed;

return out;

}

# 4.0 Commanding and Test Procedures

## 4.1 HET Aliveness Procedure

To verify that HET has been booted up correctly, run the following
aliveness procedure and view the packets on the GSE display.

### Record HK data for 7 detectors from HET GSE. It takes 5-6 minutes for data to come through after HET boots.

### Start Time: \_\_\_\_\_ HET Temperature #1 \_\_\_\_\_ HET Temperature #2 \_\_\_\_\_

Data from HET HK (dec) page on HET GSE:

+------------------+------+------+------+------+------+------+------+
|                  | **H  | **H  | **   | **   | **   | **   | **   |
|                  | 1i** | 1o** | H2** | H3** | H4** | H5** | H6** |
+------------------+------+------+------+------+------+------+------+
| **PHASIC**       |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| **Channel**      |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| **Preamp**       |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| # HG Thresh      |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| **LG Thresh**    |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| **Leakage**      |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+
| **DAC**          |      |      |      |      |      |      |      |
+------------------+------+------+------+------+------+------+------+

The following are the expected HET HK values for HET FM1 and FM2.
Compare them to the actual values above and pay attention to FM1 vs. FM2
values. Report discrepancies in the area below.

  ------------------- --------- --------- -------- -------- -------- -------- --------
                      **H1i**   **H1o**   **H2**   **H3**   **H4**   **H5**   **H6**

  **PHASIC**          0         0         1        1        1        1        1

  **Channel (FM1)**   1         11        3        5        7        9        12

  **Channel (FM2)**   1         10        2        5        7        10       13

  **Preamp (volts)**  \~4.00    \~4.00    \~4.00   \~4.00   \~4.00   \~4.00   \~4.00

  **HG Thresh (FM1)** 284       220       36       188      140      180      100

  **HG Thresh (FM2)** 192       244       124      120      68       68       30

  **LG Thresh (FM1)** 176       192       112      8        96       112      248

  **LG Thresh (FM2)** 192       192       44       56       64       52       52

  **Leakage (uA)**    \<0.5     \<0.5     \<0.5    \<2.0    \<2.0    \<2.0    \<1.0
  ------------------- --------- --------- -------- -------- -------- -------- --------

\_\_\_\_\_\_ UTC Record the H1-H6 singles rates (low gain and high gain)
for three consecutive major frames. The high-gain singles rates should
be \< 100/min., and the low-gain singles rates should be \< 5/min.

+-----------+---------+---------+--------+---------+---------+--------+
|           | **Hi    |         |        | **L     |         |        |
|           | gh-Gain |         |        | ow-Gain |         |        |
|           | Singles |         |        | Singles |         |        |
|           | Rates   |         |        | Rates   |         |        |
|           | for**   |         |        | for**   |         |        |
|           |         |         |        |         |         |        |
|           | **3     |         |        | **3     |         |        |
|           | major   |         |        | major   |         |        |
|           | f       |         |        | f       |         |        |
|           | rames** |         |        | rames** |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **Mjr Fr  |         |         |        |         |         |        |
| \#**      |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H1i**   |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H1o**   |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H2**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H3**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H4**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H5**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H6**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+

Record the following rates for one major frame. **Major Frame #:**
\_\_\_\_\_\_\_\_\_\_\_\_

  ----------------- ------------ ---------- ---------------- ------------ ----------
  **Rate Counter**  **Expected   **Actual   **Rate Counter** **Expected   **Actual
                    Counts**     Counts**                    Counts**     Counts**

  **Livetime**      \~12 x 10^6^            **Stop heavies** 0            

  **Trigger**       \<300                   **Pen H**        0            

  **Coincidence**   0                       **Pen He**       0            

  **Events**        0                       **Pen heavies**  0            

  **Singles que**   0                       **Invalid**      0            

  **Stop que**      0                       **H1 I and O**   0            

  **Pen que**       0                       **Inconsist.**   0            

  **Stop H**        0                       **H1 not first** 0            

  **Stop He**       0                       **Stim evt cnt** 0            
  ----------------- ------------ ---------- ---------------- ------------ ----------

## 4.2 SIT Aliveness Procedure

To verify that SIT has been booted up correctly, run the following
aliveness procedure and view the packets on the GSE display.

Verify SIT table checksums available in housekeeping data on SIT GSE:

  ----------------------- ----------------------- -----------------------
  **Description**         **Expected Value**      **Actual Value**

  SIT FM1 tab cksm\*      52A82E (4/28/06)        

  SIT FM2 tab cksm\*      46E9B7 (4/28/06)        
  ----------------------- ----------------------- -----------------------

\*Note: The table checksums will change when new lookup tables have been
loaded. Use the current table checksums to verify. The checksums in the
above table were correct at the time of the STEREO launch.

Verify the following singles rates on SIT GSE match expected values:

+-----------------------+---------------+------------+-----------------+
| **Description**       | **Expected    | **Actual   | **Comments**    |
|                       | Value**       | Value**    |                 |
+-----------------------+---------------+------------+-----------------+
| SRT                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| STP                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| VS                    | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| SSD                   | \<20          |            |                 |
+-----------------------+---------------+------------+-----------------+
| VSE                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| Matrix Rates (ApId    | All 0         |            |                 |
| 605)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Beacon Rates (ApId    | All 0         |            |                 |
| 619)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Pulse Height Events   | All 0         |            |                 |
|                       |               |            |                 |
| (ApId 606-617)        |               |            |                 |
+-----------------------+---------------+------------+-----------------+

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  SW Ver             0903                                     

  SW error           0 = (no error)                           

  HV Step            00                                       

  Toferror           1 = error events                         

  HV Status          0 = off                                  

  Eonly              0 = ET coincidence                       
                     required                                 

  Junk (Events)      0 = junk events                          
                     ignored                                  

  LIMHI              500                                      

  calib gain         9 - 11                                   

  calib offset       -14 to --65, should                      
                     settle at --15 but                       
                     may take as much as                      
                     an hour (don't wait                      
                     for it!).                                

  calib error        0x08, should settle                      
                     to 0x00                                  
  ------------------ --------------------- ------------------ --------------

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ----------------- ----------------- ----------------- -----------------
  **Description**   **Expected        **Actual Values** **Comments**
                    Values**                            

  HV                -79.6                               

  Tof T             25-35 C                             

  Foil T            20-25 C                             

  SSD T             20-25 C                             

  +3.3 V monitor    3.3 V                               

  +2.5 V monitor    2.5 V                               

  +5 V monitor      5 V                                 

  +6 V monitor      6 V                                 
  ----------------- ----------------- ----------------- -----------------

## 4.3 HET PHASIC Test Procedure Using Onboard Stimulus Pulser

### 4.3.1 Test Description

This comprehensive test procedure has been designed to run on either HET
flight model (FM1 and FM2). The WinMac-GSE software is required to send
the appropriate commands for configuration and to view the HET packets
to extract the relevant information for verification.

HET should be powered with the high voltage bias applied to the
detectors, and the HET flight code should be booted with the HET tables
successfully loaded. The HET flight model should be in default boot
configuration before running any test. If previous tests were conducted,
then HET should be rebooted before running any further tests.

The results of these tests will verify that the HET flight model is
operational and the flight software is accepting and processing
commands.

### Housekeeping Data

Record the housekeeping data for the seven HET detectors. If HET has
just been booted, it will take 5-7 minutes for all housekeeping data to
come through.

**Start Time: \_\_\_\_\_ HET Temperature #1 \_\_\_\_\_ HET Temperature
#2 \_\_\_\_\_**

Data from HK (dec) page:

  ------------------- --------- --------- -------- -------- -------- -------- --------
                      **H1i**   **H1o**   **H2**   **H3**   **H4**   **H5**   **H6**

  **PHASIC**                                                                  

  **Channel**                                                                 

  **Preamp**                                                                  

  **HG Thresh**                                                               

  **LG Thresh**                                                               

  **Leakage**                                                                 

  **DAC**                                                                     
  ------------------- --------- --------- -------- -------- -------- -------- --------

The following are the expected values for FM1 and FM2:

  ------------------- --------- --------- -------- -------- -------- -------- --------
                      **H1i**   **H1o**   **H2**   **H3**   **H4**   **H5**   **H6**

  **PHASIC**          0         0         1        1        1        1        1

  **Channel (FM1)**   1         11        3        5        7        9        12

  **Channel (FM2)**   1         10        2        5        7        10       13

  **Preamp (volts)**  \~4.40    \~4.40    \~4.40   \~4.40   \~4.40   \~4.40   \~4.40

  **HG Thresh (FM1)** 284       220       36       188      140      180      100

  **HG Thresh (FM2)** 192       244       124      120      68       68       30

  **LG Thresh (FM1)** 176       192       112      8        96       112      248

  **LG Thresh (FM2)** 192       192       44       56       64       52       52

  **Leakage (uA)**    \<0.5     \<0.5     \<0.5    \<2.0    \<2.0    \<2.0    \<1.0
  ------------------- --------- --------- -------- -------- -------- -------- --------

### Singles Rates / Spurious Events

Record the H1-H6 singles rates (low gain and high gain) for three
consecutive major frames. The high gain singles rates should be \<
100/min., and the low gain singles rates should be \< 5/min.

+-----------+---------+---------+--------+---------+---------+--------+
|           | **Hi    |         |        | **L     |         |        |
|           | gh-Gain |         |        | ow-Gain |         |        |
|           | Singles |         |        | Singles |         |        |
|           | Rates   |         |        | Rates   |         |        |
|           | for**   |         |        | for**   |         |        |
|           |         |         |        |         |         |        |
|           | **3     |         |        | **3     |         |        |
|           | major   |         |        | major   |         |        |
|           | f       |         |        | f       |         |        |
|           | rames** |         |        | rames** |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **Mjr Fr  |         |         |        |         |         |        |
| \#**      |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H1i**   |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H1o**   |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H2**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H3**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H4**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H5**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+
| **H6**    |         |         |        |         |         |        |
+-----------+---------+---------+--------+---------+---------+--------+

Record the following rates for one major frame. **Major Frame #:**
\_\_\_\_\_\_\_\_\_\_\_\_

  ----------------- ------------ ---------- ---------------- ------------ ----------
  **Rate Counter**  **Expected   **Actual   **Rate Counter** **Expected   **Actual
                    Counts**     Counts**                    Counts**     Counts**

  **Livetime**      \~12 x 10^6^            **Stop heavies** 0            

  **Trigger**       \<300                   **Pen H**        0            

  **Coincidence**   0                       **Pen He**       0            

  **Events**        0                       **Pen heavies**  0            

  **Singles que**   0                       **Invalid**      0            

  **Stop que**      0                       **H1 I and O**   0            

  **Pen que**       0                       **Inconsist.**   0            

  **Stop H**        0                       **H1 not first** 0            

  **Stop He**       0                       **Stim evt cnt** 0            
  ----------------- ------------ ---------- ---------------- ------------ ----------

### Event Identification / Commanding

### Stopping H Events

Send the following HET commands:

**[FM1]{.underline}** **[FM2]{.underline}**

> **tpfbsel 0 1 6 tpfbsel 0 1 6**
>
> **tpfbsel 1 5 c tpfbsel 1 5 c**
>
> **tpfbsel 1 7 c tpfbsel 1 7 c**
>
> **tpfbsel 1 9 c tpfbsel 1 a c**
>
> **tpfbsel 1 c 6 tpfbsel 1 d 6**
>
> **tpfbsel 0 b 116 tpfbsel 0 a 116**

**tpfbsel 1 3 116 tpfbsel 1 2 116**

**testp 4e2 2d 1e testp 4e2 2d 1e**

Record the following rates counters. All other rate counters should read
0.

**Major Frame** \# \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  --------------------- ---------------------------- ---------------------
  **Rate Counter**      **Expected Counts**          **Actual Counts**

  **Coincidence**       \~600                        

  **Stop que**          \~600                        

  **Stop H**            \~600                        

  **Stim evt cnt**      \~600                        
  --------------------- ---------------------------- ---------------------

### Stopping He Events

Send the following HET commands:

**[FM1]{.underline}** **[FM2]{.underline}**

> **tpfbsel 0 b 6 tpfbsel 0 a 6**

**tpfbsel 0 1 116 tpfbsel 0 1 116**

> **tpfbsel 1 5 12c tpfbsel 1 5 12c**

**testp 4e2 10f 1e testp 4e2 10f 1e**

Record the following rates counters. All other rate counters should read
0.

**Major Frame** \# \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  ---------------------- -------------------------- ----------------------
  **Rate Counter**       **Expected Counts**        **Actual Counts**

  **Coincidence**        \~600                      

  **Stop que**           \~600                      

  **Stop He**            \~600                      

  **Stim evt cnt**       \~600                      
  ---------------------- -------------------------- ----------------------

### Stopping Z\>2 Events

Send the following HET commands:

**[FM1]{.underline}** **[FM2]{.underline}**

> **tpfbsel 0 1 6 tpfbsel 0 1 6**
>
> **tpfbsel 0 b 116 tpfbsel 0 a 116**

**tpfbsel 1 5 11c tpfbsel 1 5 11c**

**testp 4e2 179 3d testp 4e2 179 3d**

Record the following rates counters. All other rate counters should read
0.

**Major Frame** \# \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  --------------------- ------------------------ ------------------------
  **Rate Counter**      **Expected Counts**      **Actual Counts**

  **Coincidence**       \~600                    

  **Stop que**          \~600                    

  **Stop heavies**      \~600                    

  **Stim evt cnt**      \~600                    
  --------------------- ------------------------ ------------------------

### Penetrating H Events

Send the following HET commands:

**[FM1]{.underline}** **[FM2]{.underline}**

> **tpfbsel 1 3 126 tpfbsel 1 2 126**
>
> **tpfbsel 1 7 11c tpfbsel 1 7 11c**

**tpfbsel 1 9 11c tpfbsel 1 a 11c**

**tpfbsel 1 c 116 tpfbsel 1 d 116**

**testp 4e2 17 b testp 4e2 16 a**

Record the following rates counters. All other rate counters should read
0.

**Major Frame** \# \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  --------------------- -------------------------- -----------------------
  **Rate Counter**      **Expected Counts**        **Actual Counts**

  **Coincidence**       \~600                      

  **Pen que**           \~600                      

  **Pen H**             \~600                      

  **Stim evt cnt**      \~600                      
  --------------------- -------------------------- -----------------------

### Stimulus Pulser / Analog Channels (FM1 only, skip to step 6 for FM2)

First, send the following HET commands:

> **gwrite 9 32**
>
> **tmode 3**
>
> **hgorsel 1 0 12a8**
>
> **lgorsel 1 0 12a8**

The next section has been designed to pulse all the channels (H1i, H1o,
H2, H3, H4, H5, H6). The command set should be sent and the data values
should be reviewed and recorded at each configuration as directed. It
should be noted that the expected pulse height value range may not be
exact, but the values should lie very close to this range.

### Configure All Channels

### 

> Send the following HET command set to configure the channels as
> follows:

-   enable the test pulser for all channels

-   set the feedback capacitor to 30pF for H1i, H1o, H2 and H6

-   set the feedback capacitor to 60pF for H3, H4 and H5

-   set the test input capacitor to 18pF for H1i, H1o, H2 and H6

-   set the test input capacitor to 36pF for H3, H4 and H5

> **tpfbsel 0 1 166**
>
> **tpfbsel 0 b 166**
>
> **tpfbsel 1 3 166**
>
> **tpfbsel 1 5 1cc**
>
> **tpfbsel 1 7 1cc**
>
> **tpfbsel 1 9 1cc**
>
> **tpfbsel 1 c 166**
>
> Send the following HET command set to configure the channels as
> follows:

-   disable the high gain ADC for all channels

-   enable the low gain ADC for all channels

> **phacont 0 1 7**
>
> **phacont 0 b 7**
>
> **phacont 1 3 7**
>
> **phacont 1 5 7**
>
> **phacont 1 7 7**
>
> **phacont 1 9 7**
>
> **phacont 1 c 7**
>
> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to 5V

-   set the Phasic 1 DAC setting to 5V

> **testp 4e2 1ff 1ff**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------------ ------------------ --------------
  **Channel**   **Expected Range**       **Actual Range**   **Mjr Fr #s**

  H1i           08c813 -- 08c818                            

  H1o           05c80b -- 05c80f                            

  H2            11c804 -- 11c808                            

  H3            12c830 -- 12c834                            

  H4            13c818 -- 13c81d                            

  H5            14c824 -- 14c828                            

  H6            96481c -- 964821                            
  ------------- ------------------------ ------------------ --------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to 2.51V

-   set the Phasic 1 DAC setting to 2.51V

> **testp 4e2 180 180**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           08c423 -- 08c425                        

  H1o           05c41d -- 05c420                        

  H2            11c41a -- 11c41c                        

  H3            12c42e -- 12c430                        

  H4            13c422 -- 13c425                        

  H5            14c428 -- 14c42a                        

  H6            964425 -- 964427                        
  ------------- ------------------- ------------------- -------------------

> Send the following command set to configure all the channels to the
> following:

-   enable the high gain ADC for all channels

-   enable the low gain ADC for all channels

-   verbose mode off

**phacont 0 1 d**

**phacont 0 b d**

**phacont 1 3 d**

**phacont 1 5 d**

**phacont 1 7 d**

**phacont 1 9 d**

**phacont 1 c d**

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to .25V

-   set the Phasic 1 DAC setting to .25V

> **testp 4e2 ff ff**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           0887e7 -- 0887eb                        

  H1o           0587cb -- 0587d0                        

  H2            1187eb -- 1187f0                        

  H3            1287ec -- 1287f0                        

  H4            1387e8 -- 1387ed                        

  H5            1487de -- 1487e2                        

  H6            9607f6 -- 9607fb                        
  ------------- ------------------- ------------------- -------------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to 0.125V

-   set the Phasic 1 DAC setting to 0.125V

> **testp 4e2 80 80**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           08840b -- 088410                        

  H1o           0583fd -- 058401                        

  H2            11840c -- 118410                        

  H3            12840c -- 128410                        

  H4            13840a -- 13840f                        

  H5            148405 -- 148409                        

  H6            960411 -- 960416                        
  ------------- ------------------- ------------------- -------------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to .002V

-   set the Phasic 1 DAC setting to .002V

> **testp 4e2 2 2**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           08803d - 088040                         

  H1o           05803b -- 05803f                        

  H2            11803b -- 11803e                        

  H3            12803a -- 12803e                        

  H4            13803b -- 13803e                        

  H5            14803a -- 14803e                        

  H6            96003a -- 96003e                        
  ------------- ------------------- ------------------- -------------------

Finally, send the following HET commands or reboot:

> **testp 4e2 0 0**
>
> **gwrite 9 30**
>
> **tmode 0**
>
> **hgorsel 1 0 8**
>
> **lgorsel 1 0 8**
>
> **tpfbsel 0 1 6**
>
> **tpfbsel 0 b 6**
>
> **tpfbsel 1 3 6**
>
> **tpfbsel 1 5 c**
>
> **tpfbsel 1 7 c**
>
> **tpfbsel 1 9 c**
>
> **tpfbsel 1 c 6**
>
> **testp auto**

***\*\*\* END OF TEST FOR FM1. STOP HERE IF TESTING FM1.\*\*\****

### Stimulus Pulser / Analog Channels (FM2 only)

First, send the following HET commands:

> **gwrite 9 32**
>
> **tmode 3**
>
> **hgorsel 1 0 24a4**
>
> **lgorsel 1 0 24a4**

### Configure All Channels

> Send the following HET command set to configure the channels as
> follows:

-   enable the test pulser for all channels

-   set the feedback capacitor to 30pF for H1i, H1o, H2 and H6

-   set the feedback capacitor to 60pF for H3, H4 and H5

-   set the test input capacitor to 18pF for H1i, H1o, H2 and H6

-   set the test input capacitor to 36pF for H3, H4 and H5

> **tpfbsel 0 1 166**
>
> **tpfbsel 0 a 166**
>
> **tpfbsel 1 2 166**
>
> **tpfbsel 1 5 1cc**
>
> **tpfbsel 1 7 1cc**
>
> **tpfbsel 1 a 1cc**
>
> **tpfbsel 1 d 166**
>
> Send the following HET command set to configure the channels as
> follows:

-   disable the high gain ADC for all channels

-   enable the low gain ADC for all channels

> **phacont 0 1 7**
>
> **phacont 0 a 7**
>
> **phacont 1 2 7**
>
> **phacont 1 5 7**
>
> **phacont 1 7 7**
>
> **phacont 1 a 7**
>
> **phacont 1 d 7**
>
> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to 5V

-   set the Phasic 1 DAC setting to 4.71V

> **testp 4e2 1ff 1f0**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------------ ------------------ --------------
  **Channel**   **Expected Range**       **Actual Range**   **Mjr Fr #s**

  H1i           08c816 -- 08c818                            

  H1o           054808 -- 05480d                            

  H2            1147e8 -- 1147ed                            

  H3            12c7ea -- 12c7ef                            

  H4            13c7f0 -- 13c7f5                            

  H5            1547ea -- 1547ef                            

  H6            96c7dc -- 96c7e1                            
  ------------- ------------------------ ------------------ --------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to 2.51V

-   set the Phasic 1 DAC setting to 2.51V

> **testp 4e2 180 180**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           08c423 -- 08c426                        

  H1o           05441c-- 05441e                         

  H2            11444b -- 11444e                        

  H3            12c44c -- 12c44e                        

  H4            13c44f -- 13c451                        

  H5            15444c -- 15444e                        

  H6            96c444 -- 96c447                        
  ------------- ------------------- ------------------- -------------------

> Send the following command set to configure all the channels to the
> following:

-   enable the high gain ADC for all channels

-   enable the low gain ADC for all channels

-   verbose mode off

> **phacont 0 1 d**
>
> **phacont 0 a d**
>
> **phacont 1 2 d**
>
> **phacont 1 5 d**
>
> **phacont 1 7 d**
>
> **phacont 1 a d**
>
> **phacont 1 d d**
>
> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to .25V

-   set the Phasic 1 DAC setting to .235V

> **testp 4e2 ff f0**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           0887cc -- 0887d1                        

  H1o           0507d2 -- 0507d6                        

  H2            1107c9 -- 1107cd                        

  H3            1287ad -- 1287b1                        

  H4            1387af -- 1387b4                        

  H5            1507b4 -- 1507b8                        

  H6            9687a3 -- 9687a8                        
  ------------- ------------------- ------------------- -------------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to .125V

-   set the Phasic 1 DAC setting to .125V

> **testp 4e2 80 80**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           0883fd -- 088402                        

  H1o           0503ff -- 050404                        

  H2            110439 -- 11043e                        

  H3            12842a -- 12842f                        

  H4            13842b -- 138430                        

  H5            15042e -- 150432                        

  H6            968425 -- 968429                        
  ------------- ------------------- ------------------- -------------------

> Send the following HET command to configure the following:

-   set the test pulser frequency to 10 pulses per second

-   set the Phasic 0 DAC setting to .002V

-   set the Phasic 1 DAC setting to .002V

> **testp 4e2 2 2**
>
> Wait about 2-3 minutes and then record the range of raw data observed
> (a 6-digit hex number, the last three of which represent the actual
> pulse height) using raw data (pulse heights from packet 597:

  ------------- ------------------- ------------------- -------------------
  **Channel**   **Expected Range**  **Actual Range**    **Mjr Fr #s**

  H1i           08803c -- 08803f                        

  H1o           05003b -- 05003e                        

  H2            11003d -- 110041                        

  H3            12803d -- 128041                        

  H4            13803d -- 138040                        

  H5            15003d -- 150040                        

  H6            96803c -- 96803f                        
  ------------- ------------------- ------------------- -------------------

Finally, send the following HET commands or reboot:

> **testp 4e2 0 0**
>
> **gwrite 9 30**
>
> **tmode 0**
>
> **hgorsel 1 0 4**
>
> **lgorsel 1 0 4**
>
> **tpfbsel 0 1 6**
>
> **tpfbsel 0 a 6**
>
> **tpfbsel 1 2 6**
>
> **tpfbsel 1 5 c**
>
> **tpfbsel 1 7 c**
>
> **tpfbsel 1 a c**
>
> **tpfbsel 1 d 6**
>
> **testp auto**

## 4.4 SIT Comprehensive Test Procedure (In Flight)

Send the following SIT commands:

**immed 1** causes all commands to be executed upon receipt

**hvenable 0** ensures that the SIT HVPS is disabled

**junk 1** causes SIT to respond to all events, even illegals

**eonly 1** removes TOF coincidence requirement for events

**toferror 1** processes events including TOF errors

**limhi 100**

Verify SIT is configured for quiet mode. After several minutes, verify
the parameters from the display with the values in the following table.
These parameters will verify that SIT is in quiet mode.

:

  ----------------------------------- -----------------------------------
  **Description**                     **Expected Value**

  Toferror                            1

  HV Status                           0

  Eonly                               1

  Junk                                1

  Limhi                               256
  ----------------------------------- -----------------------------------

**Verify SIT is configured in noisy mode**

Send the following **HAZARDOUS COMMANDS**.

**[Double-check the commands before sending them.]{.underline}**

**hvenable 1** enables the SIT HVPS

**hvlevel 10** sets the HVPS output to about 300V

Wait 2-3 minutes for the new telemetry and then verify the following
status information has been returned on SIT GSE and matches expected
values:

  ----------------------------------- -----------------------------------
  **Description**                     **Expected Value**

  HV Step                             10

  Toferror                            1

  HV status                           1

  Eonly                               1

  Junk                                1

  HV                                  300-350 V
  ----------------------------------- -----------------------------------

After 5 minutes after beginning of SIT Noisy Mode send the following
commands to turn off the HV.

**hvenable 0** ensures that the SIT HVPS is disabled

**hvlevel 0** sets HV level to 0

**junk 0** causes instrument to reject illegal events

**eonly 0** removes TOF coincidence requirement for events

**toferror 0** processes events including TOF errors

**limhi 1f4** limits high-priority events to 500/major frame

Wait 2-3 minutes for the new telemetry. In the meantime, continue with
other Step 4 activities in parallel and verify the following status
information has been returned on SIT GSE and matches expected values:

  ----------------------------------- -----------------------------------
  **Description**                     **Expected Value**

  HV Step                             00

  Toferror                            0

  HV Status                           0

  Eonly                               0

  Junk                                0

  Limhi                               500
  ----------------------------------- -----------------------------------

## 4.5 SIT High Voltage Power Supply Turn On Procedure (In Flight)

The SIT high voltage turn-on takes 5 days to reach the operating voltage
of \~3000v. This procedure assumes that the instrument will be powered
on continuously for 5 consecutive days.

Verify SIT table checksums available in housekeeping data on SIT GSE:

  ----------------------- ----------------------- -----------------------
  **Description**         **Expected Value**      **Actual Value**

  SIT FM1 tab cksm        52A82E (4/28/06)        

  SIT FM2 tab cksm        46E9B7 (4/28/06)        
  ----------------------- ----------------------- -----------------------

Verify the following singles rates on SIT GSE match expected values
(cts/min):

+-----------------------+---------------+------------+-----------------+
| **Description**       | **Expected    | **Actual   | **Comments**    |
|                       | Value**       | Value**    |                 |
+-----------------------+---------------+------------+-----------------+
| SRT                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| STP                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| VS                    | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| SSD                   | \>600         |            |                 |
+-----------------------+---------------+------------+-----------------+
| VSE                   | 0             |            |                 |
+-----------------------+---------------+------------+-----------------+
| Matrix Rates (ApId    | All 0         |            |                 |
| 605)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Beacon Rates (ApId    | All 0         |            |                 |
| 619)                  |               |            |                 |
+-----------------------+---------------+------------+-----------------+
| Pulse Height Events   | All 0         |            |                 |
|                       |               |            |                 |
| (ApId 606-617)        |               |            |                 |
+-----------------------+---------------+------------+-----------------+

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  SW Ver             0602                                     

  SW error           0 = (no error)                           

  HV Step            00                                       

  Toferror           0 = error events                         

  HV Status          0 = off                                  

  Eonly              0 = ET coincidence                       
                     required                                 

  Junk (Events)      0 = junk events                          
                     ignored                                  

  LIMHI              500                                      

  calib gain         9 - 11                                   

  calib offset       -14 to --65, should                      
                     settle at --15 but                       
                     may take as much as                      
                     an hour (don't wait                      
                     for it!).                                

  calib error        0x08, should settle                      
                     to 0x00                                  
  ------------------ --------------------- ------------------ --------------

Verify the following status information has been returned on SIT GSE and
matches expected values:

  ----------------- ----------------- ----------------- -----------------
  **Description**   **Expected        **Actual Values** **Comments**
                    Values**                            

  HV                -79.6                               

  Tof T             25-35 C                             

  Foil T            20-25 C                             

  SSD T             20-25 C                             

  +3.3 V monitor    3.3 V                               

  +2.5 V monitor    2.5 V                               

  +5 V monitor      5 V                                 

  +6 V monitor      6 V                                 
  ----------------- ----------------- ----------------- -----------------

**Command sequence for HVPS turn on**

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 1
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Commands:

**immed 1**

**hvenable 1**

**CAUTION: the following is a hazardous command. Check carefully before
sending**

**hvramp 40**

> After 2-3 minutes, verify the HV setting and count rates:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            40                                       

  HV                 985 - 1045                               

  HV Status          1 = on                                   

  SRT                0                                        

  STP                0                                        

  VS                 0                                        

  SSD                \>600                                    

  VSE                0                                        
  ------------------ --------------------- ------------------ --------------

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp 80**

> After 2-3 minutes, verify the HV setting and count rates:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            80                                       

  HV                 2063 - 2156                              

  HV Status          1 = on                                   

  SRT                0-10                                     

  STP                0-10                                     

  VS                 0-10                                     

  SSD                \>600                                    

  VSE                0-10                                     
  ------------------ --------------------- ------------------ --------------

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp 90**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            90                                       

  HV                 2345 - 2422                              

  HV Status          1 = on                                   

  SRT                \>10                                     

  STP                \>10                                     

  VS                 \>0                                      

  SSD                \>600                                    

  VSE                \>0                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 2
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp a0**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            A0                                       

  HV                 2610 - 2704                              

  HV Status          1 = on                                   

  SRT                \>10                                     

  STP                \>10                                     

  VS                 \>0                                      

  SSD                \>600                                    

  VSE                \>0                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 3
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp a8**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            A8                                       

  HV                 2760 - 2853                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day
4\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully.**

**hvramp b0**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            B0                                       

  HV                 2843 - 2986                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

**\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Day 5
\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\***

Send the SIT Command:

**CAUTION: the following is a hazardous command. Check carefully before
sending**

**hvramp b8**

> After 2-3 minutes, verify the HV setting:

  ------------------ --------------------- ------------------ --------------
  **Description**    **Expected Value**    **Actual Value**   **Comments**

  HV Step            B8                                       

  HV                 2976 - 3109                              

  HV Status          1 = on                                   

  SRT                \>100                                    

  STP                \>100                                    

  VS                 \>1                                      

  SSD                \>600                                    

  VSE                \>1                                      
  ------------------ --------------------- ------------------ --------------

\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

Notes:

\(1\) range of expected HV values based on range between fm1 and fm2
hot/cold cases observed during thermal vac, ± 30 V allowance for 2
channel jitter in ADC

\(2\) range of expected count rates in detectors variable due to
diferent levels of activity observed in IP space. Figure below shows
COUNTS/SECOND for Wind/STEP for comparable count rates during first
portion of 2006

![](media/image2.wmf){width="5.998611111111111in"
height="6.658333333333333in"}