Advantest R6581 Schematic Diagrams - Page 1
Forum section: electronics / general

author: Mickle T.
author_rank: Frequent Contributor
timestamp: April 08, 2018, 08:07:30 pm
content: Schematic diagrams:https://drive.google.com/open?id=168OEKv1ZXCj0otQcDKMG1uXkSvPy_49JAll other R6581 stuff is here:https://drive.google.com/open?id=1_dyCk3kvzEaxp3uqANyhvvmRXCpOAnJoFull archive was uploaded to KO4BB.

author: 2N3055
author_rank: Super Contributor
timestamp: April 08, 2018, 11:02:49 pm
content: Fantastic work!Thanks!

author: wutieru
author_rank: Contributor
timestamp: April 09, 2018, 12:22:40 am
content: I have been looking for this Schematic for many years?Thanks a lot?

author: zhtoor
author_rank: Frequent Contributor
timestamp: April 09, 2018, 01:14:06 am
content: @Mickle T.i vote for awarding you the "MASTER OF VOLTNUTS" awardbest regards.-zia

author: quarks
author_rank: Frequent Contributor
timestamp: April 11, 2018, 06:42:40 pm
content: many thanks

author: Mickle T.
author_rank: Frequent Contributor
timestamp: May 26, 2018, 07:34:14 pm
content: Schematic diagrams is updated to v.4 in post #1: some minor bugs was fixed, measured all of the film capacitors.Firmware reversing is in progress. To date i have disassembled all EPROM code and identified all RTOS VRTX32/68k system calls, exception vectors, IRQ handers, internal hardware registers, reset and early initialization procedures and many other low-level things.Problem #1 at the moment - too many chips on the digital boards with unknown address space decodingProblem #2 - an ancient Xilinx FPGA in the middle of the main digital board

author: TiN
author_rank: Super Contributor
timestamp: May 27, 2018, 04:54:08 am
content: If you need some logic analyzer measurements, let me know.I can hook up my LA to capture the waveforms (272 channels should be enough?.

author: Mickle T.
author_rank: Frequent Contributor
timestamp: June 17, 2018, 08:20:56 am
content: All of the above-mentioned problems is solved by hand without any LA or scope.Advantest R6581 reversing project is closed now. At least until I get a ACV board or full non-T R6581

author: eurofox
author_rank: Unknown
timestamp: June 17, 2018, 08:39:45 am
content: Quote from: Mickle T. on June 17, 2018, 08:20:56 amGlad that you finally manage to fix the instrument, I'm quite happy with mine, it is maybe not so good as the 3458A but I think it is in the area of a Keithley 2002.I hope soon to be able to meet someone in a calibration LAB or private person with a recent calibrated 3458A or with a calibrated 10V reference.I have a near 0 temco 10K resistor. Of course I'm ready to pay for this, it take one hour or more to warm up the instrument and only 10 minutes for an external calibration, I don't need any report.If someone can help me in Belgium, France, Holland or Germany just let me know up to 600 kms from Brussels.

author: TiN
author_rank: Super Contributor
timestamp: June 17, 2018, 08:57:14 am
content: QuoteNop, it's not in 2002 league either. And 2002 resistance performance is bit better than 3458 minus the ACAL.At least both of my 2002s show better stability on 1K-100K values than my 3458s.I think Mickle.T meant that he reversed logic connections and mapping, but that does not mean analog issues are fixed.

author: eurofox
author_rank: Unknown
timestamp: June 17, 2018, 10:22:42 am
content: Quote from: TiN on June 17, 2018, 08:57:14 amIs your R6581 fully operational now? Last information I remember is that display was barely visible showing long power up life, the test that you ask met to perform on my system did not perform well on yours, I remembered the polarity, the resistance check ....I would like to check mine near a calibrated 3458A or 2002 to judge. I have a 2001 100% OK but need calibration as well.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 17, 2018, 11:02:57 am
content: Noise wise the 6581T might be about on par with the Keithley2002, maybe a little better. However the Ohms ranges are likely worse, especially high higher ohms ones. The ACAL scheme needs a lot of steps for all the Ohms ranges and also for the higher currents. Here the non ACAL scheme with separate reference resistors in the K2002 has an advantage - at the price of a larger number or critical parts and the more complicated calibration (not just 10 V and 10 K, but separate Ohms ranges and currents). Similar for the currents, especially the higher currents where the test current from the ohms source is limited.As far as I understood it, there was only a partial fix to the problems (faster guard amplifier directly from the input - which reduces the input current spikes at highly negative voltage).Still there seem to be quite a few of the meters to show excessive INL and the higher Ohms ranges seem to have a problem. The input current when in < 10 PLC AZ mode also seems to be quite high due to the missing pre-charge phase. This is kind of a weakness by design. This also includes the additional switching related current spike with voltages beyond about -7 V.@Eurofox: It might be interesting to see the test for input current for a seemingly good meter. That is recoding the discharge curves with a good quality (e.g PP / PS) 1-10 nF capacitor in the 10 V , 1 PLC AZ mode, and maybe without AZ.

author: eurofox
author_rank: Unknown
timestamp: June 17, 2018, 11:46:31 am
content: Quote from: Kleinstein on June 17, 2018, 11:02:57 amI suppose this configuration?

author: TiN
author_rank: Super Contributor
timestamp: June 17, 2018, 11:52:51 am
content: No, just cap across the 6581 terminals. Log data with meter itself, once cap is charged to 10V and then switch open.Siglent is useless to measure bias currents of HiZ meter.

author: eurofox
author_rank: Unknown
timestamp: June 17, 2018, 10:05:21 pm
content: Quote from: TiN on June 17, 2018, 11:52:51 amI know that the curent is very low because the very impedance of the meter, I was just trying to understand how you proceed based on explanations of Kleinstein.I don't have a high quality capacitor in my home collection, I was in the shop yesterday, they have a full range in this shop of audio Polypropylene capacitors, I just order some on internet, it take me 2 hours to drive to the shop and backThe problem with your procedure it is not easy to record the data with time information, it should be done by communication with GPIB and output to a PC with trending, it is one of my project on the list.But due to the very high impedance discharging is maybe very slow ...

author: TiN
author_rank: Super Contributor
timestamp: June 18, 2018, 09:42:19 am
content: Sorry, but anyone who is going to do anything useful with 8.5digit meter must have a setup to log timestamped data with attached environment conditions. This is the basics when you entering this realm. RPi + one of available GPIB dongles would pay for itself many times over the time, if you into this game.

author: eurofox
author_rank: Unknown
timestamp: June 18, 2018, 10:39:11 am
content: Quote from: TiN on June 18, 2018, 09:42:19 amI already got a genuine USB - GPIB Keysight interface since more than 2 months, got connection cables last week.I have now a temperature and humidity logger with PC interface.I'm checking now on the PC side, NI, Excel or any other interface but no Python, I already know basic, vb, C, C++, assembly, Pascal and that is enough

author: eurofox
author_rank: Unknown
timestamp: June 18, 2018, 04:50:55 pm
content: Those strings you have to send to the R6581 to read data.I try with Excel but it is slowRange 10V DC and one NPLCinstrument.WriteString "*RST"instrument.WriteString "CONF:VOLT:DC"instrument.WriteString "VOLT:DC:RANG 10;NPLC 1"instrument.WriteString "ARM:SOUR IMM"instrument.WriteString "ARM:LAY2:SOUR IMM"instrument.WriteString "TRIG:SOUR IMM"instrument.WriteString "INIT:CONT OFF"instrument.WriteString "ABORT"instrument.WriteString "READ?"

author: Mickle T.
author_rank: Frequent Contributor
timestamp: June 24, 2018, 03:10:58 pm
content: In response to a z01z question about R6581 accessory detection code.R6581 extention cards interface is not as simple as it appears. It have a 8-bit local data bus (buffered from 16-bit MPU data bus with U22 74HC245), 8-bit local address bus (A1-A8 MPU address lines, buffered with U23 74HC38245), high address lines decoder (PAL U114 e.t.c.), interface enable line (bit #3 port B of PPI U108 82C55), 3 (or more) lines from magical FPGA...

author: z01z
author_rank: Regular Contributor
timestamp: June 24, 2018, 05:33:14 pm
content: Mickle T., thanks a lot for sharing this!

author: z01z
author_rank: Regular Contributor
timestamp: June 24, 2018, 05:50:58 pm
content: Regarding the address decoding table, it is said in the manual that the SRAM card can be 2MB maximum. It makes sense, since 2MB will occupy the whole address range of 800000-FFFFFF.

author: eurofox
author_rank: Unknown
timestamp: June 25, 2018, 04:40:33 pm
content: Quote from: TiN on June 18, 2018, 09:42:19 amSecond vs Volts, zero will take several hours, capacitor is 5.6NF.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 25, 2018, 05:10:03 pm
content: The seconds over volts is an slightly usual plot. The more normal way would be to have the time horizontal. Still one can read the input current: for the 10-7 V range it's about 200 seconds for 3.5 V and thus around 100 pA of input current at some 7-10 V. This is not that bad - other such meters had more input current. It also depends on the more used - I would guess this to be in a non AZ mode. The input current is expected to be higher in AZ mode, especially with 1 PLC mode as there is extra switching related current.Anyway the discussion is a bit off topic for this thread and might better move to the repair/tear-down thread.

author: eurofox
author_rank: Unknown
timestamp: June 25, 2018, 05:33:26 pm
content: Quote from: Kleinstein on June 25, 2018, 05:10:03 pmI will make a new one in "repair" but I'm convince that my DMM is OK.Record with a good quality capacitor 100PLC and AZ mode. I agree that the graph should be time in horizontal, I just finished replacing the bindings posts by "good ones"

author: z01z
author_rank: Regular Contributor
timestamp: June 26, 2018, 06:33:39 am
content: Attached is the draft of the digital circuitry schematic from the analog out board. Seems like the same circuit is also used for the analog, printer and bcd boards, only the ID resistor is moved to a different position. Power-on test is successful and the different accessories are recognized when the resistor is moved around.Moving the resistor to the scanner position gives 201 interface error though. After seeing the code this is not surprising, there are extra checks for the scanner, which checks some extra hardware.The connector is Hirose FX2-52S-1.27DSL(71).