EB 8389-2 EN
Translation of original instructions

EXPERTplus Valve Diagnostics
TROVIS 3793 Electropneumatic Positioner

Firmware version 1.01.xx
Edition March 2023

Documents relating to the device, such as the mounting and operating
instructions, are available on our website at www.samsongroup.com >Service & Support > Downloads > Documentation.

Definition of signal words! DANGER
Hazardous situations which, if not avoided,
will result in death or serious injury! WARNING
Hazardous situations which, if not avoided,
could result in death or serious injury! NOTICE
Property damage message or malfunction
Note
Additional information
Tip
Recommended action

EB 8389-2 EN

Contents1
1.1

Safety instructions and measures....................................................................5
Notes on possible property damage.................................................................7

2
2.1
2.1.1
2.2

Operation......................................................................................................8
Operation using TROVIS-VIEW/DD/DTM/EDD................................................8
Operation using TROVIS-VIEW........................................................................8
On-site operation............................................................................................93
3.1

Start-up.........................................................................................................9
Signal pressure limitation...............................................................................11

4
4.1
4.2
4.2.1

Configuration...............................................................................................13
Limits...........................................................................................................13
Status classification.......................................................................................14
Reset............................................................................................................15

5
5.1
5.1.1
5.2
5.2.1
5.3
5.3.1
5.4
5.4.1

Device state.................................................................................................16
Information parameters.................................................................................16
Reset............................................................................................................16
Status messages............................................................................................18
Group and condensed states..........................................................................18
Logging........................................................................................................18
Reset............................................................................................................19
Temperature.................................................................................................20
Reset............................................................................................................20

6
6.1
6.1.1
6.1.2
6.1.3
6.1.4
6.2
6.2.1
6.2.1.1
6.2.2
6.2.2.1
6.3
6.3.1
6.4
6.4.1
6.4.1.1

Statistical information...................................................................................21
Histograms...................................................................................................21
Reset............................................................................................................21
Valve position...............................................................................................22
Set point deviation........................................................................................23
Load cycle....................................................................................................24
Course of end position..................................................................................25
Course of lower end position.........................................................................26
Reset............................................................................................................27
Course of upper end position.........................................................................27
Reset............................................................................................................27
Course of supply pressure..............................................................................29
Reset............................................................................................................29
Valve signature.............................................................................................30
Recording reference graphs...........................................................................30
Reset............................................................................................................32

EB 8389-2 EN

Contents

6.4.2
6.4.2.1
6.4.3
6.5
6.5.3.1

Monitoring...................................................................................................32
Reset............................................................................................................33
Friction.........................................................................................................33
Leakage sensor.............................................................................................35
Reset............................................................................................................36

7
7.1
7.1.1
7.1.2
7.1.2.1
7.1.2.2
7.1.2.3
7.1.3
7.1.4
7.2
7.2.1
7.2.2
7.2.2.1
7.2.2.2
7.2.3
7.2.4
7.3
7.3.1
7.4

Tests............................................................................................................37
Partial stroke test (PST)...................................................................................37
Test cancellation criteria.................................................................................38
Test start.......................................................................................................40
Manual start.................................................................................................40
Automatic start after 'Test interval' has elapsed................................................41
Start triggered by binary input.......................................................................41
Analysis and monitoring................................................................................41
Reset............................................................................................................44
Full stroke test (FST).......................................................................................45
Test cancellation criteria.................................................................................46
Test start.......................................................................................................46
Manual start.................................................................................................47
Start triggered by binary input.......................................................................47
Analysis and monitoring................................................................................47
Reset............................................................................................................49
Dead band...................................................................................................51
Reset............................................................................................................52
Valve signature (Tests)....................................................................................53

8

Error messages and recommended corrective action......................................55

EB 8389-2 EN

Safety instructions and measures

1 Safety instructions and measures
Intended use
EXPERTplus is a diagnostic firmware integrated into the positioner which allows the predictive, status-oriented maintenance of valves with pneumatic actuators.
EXPERTplus records the valve condition while the process is running (in automatic mode) andgenerates messages on the required maintenance work. In addition, numerous tests can be
performed in manual mode to pinpoint emerging faults.
The diagnostic functions of EXPERTplus are fully integrated into the positioner. Diagnostic data are compiled, saved and analyzed in the positioner itself. Classified status messages on
the state of the valve are generated from the analysis.
Reasonably foreseeable misuse
While the tests are being performed, the valve does not follow the set point. Instead, it is
moved according to the specifications of the test procedure. Therefore, the tests can only be
started when the conditions in the plant allow it.
Qualifications of operating personnel
The devices must be configured and set by trained and experienced personnel only. According to these operating instructions, trained personnel refers to individuals who are able tojudge the work they are assigned to and recognize possible hazards due to their specialized
training, their knowledge and experience as well as their knowledge of the applicable standards.
Personal protective equipment
No personal protective equipment is required for the direct handling of the valve diagnostics
integrated into the positioner. Work on the control valve may be necessary when mounting
or removing the device.
Î Observe the requirements for personal protective equipment specified in the valve documentation.
Î Check with the plant operator for details on further protective equipment.
Revisions and other modifications
Revisions or other modifications of the product are not authorized by SAMSON. They are
performed at the user's own risk and may lead to safety hazards, for example. Furthermore,
the product may no longer meet the requirements for its intended use.

EB 8389-2 EN

5

Safety instructions and measures

Safety features
Diagnostic settings can be performed on site at the positioner or using the TROVIS-VIEW
software or DD, DTM and EDD.
The TROVIS-VIEW software only has a direct influence on the connected positioner while data are being exchanged between the software and positioner (online mode).
Warning against residual hazards
Diagnostic settings, which can be performed on site at the positioner or, when the data connection is active, using the TROVIS-VIEW software or DD, DTM and EDD, have a direct influence on the control valve. To avoid personal injury or property damage, plant operators andoperating personnel must prevent hazards that could be caused in the control valve by theprocess medium, the operating pressure, the signal pressure or by moving parts by taking
appropriate precautions. Plant operators and operating personnel must observe all hazard
statements, warning and caution notes in the referenced documents.
Responsibilities of the operator
Operators are responsible for proper use and compliance with the safety regulations. The
operator is obliged to provide these operating instructions as well as the referenced documents to the operating personnel and to instruct them in proper operation. Furthermore, operators must ensure that operating personnel or third parties are not exposed to any danger.
Responsibilities of operating personnel
Operating personnel must read and understand these operating instructions as well as thereferenced documents and observe the specified hazard statements, warnings and caution
notes. Furthermore, operating personnel must be familiar with the applicable health, safety
and accident prevention regulations and comply with them.
Referenced standards, directives and regulations
None
Referenced documentation
The following documents apply in addition to these operating instructions:− Mounting and operating instructions (EB) and configuration manual (KH) for mounted device:u EB 8493 and u KH 8384-3− Mounting and operating instructions for the associated control valve (actuator, valve andother valve accessories)

6

EB 8389-2 EN

Safety instructions and measures

1.1 Notes on possible property damage! NOTICE
Valve malfunction due to a configuration and parameter settings that do not meetthe requirements of the application.
Settings for the EXPERTplus valve diagnostics can be made in the TROVIS-VIEW software. In online mode of this software, the configuration and parameter settings take effect immediately in the connected positioner and affect the control valve as a result.
Î Only activate the online mode when configurations, parameter settings and measured values are to be transferred from or to the device.
Manipulation of the configuration due to unauthorized access.
The positioner can be protected against unauthorized access through the use of a customized password. The password can be activated and changed in the software.
Î Do not pass the password on to unauthorized persons. Keep it in a safe place inaccessible to unauthorized persons.

EB 8389-2 EN

7

Operation

2 Operation
2.1 Operation using TROVISVIEW/DD/DTM/EDD
EXPERTplus allows the parameters to beviewed or changed using the TROVIS-VIEW
software or DD/DTM/EDD.
− TROVIS-VIEW · SAMSON user interface
used to configure various SAMSON
devices. Software download
u www.samsongroup.com > SERVICE &SUPPORT > Downloads > TROVIS-VIEW− DTM · Device type manager to describe
the device and communication
properties. Integration fileu www.samsongroup.com > SERVICE &SUPPORT > Downloads > Device
integration

2.1.1

Operation using
TROVIS-VIEW

Operation using TROVIS-VIEW is describedin these operating instructions. The following
applies in this case:− The default settings of parameters are
written in square brackets [ ].
− Operation applies to the 'Diagnosis' userlevel.
− Descriptions that apply to the 'Customer
expert' user lever are marked.
Î Contact SAMSON's After-sales Service to obtain access to the 'Customer
expert' user level.

− EDD · Electronic Device Description. Integration file u www.samsongroup.com >SERVICE & SUPPORT > Downloads >Device integration

Note
The installation and operation of the
TROVIS-VIEW software is explained in detailin the Operating Instructions u EB 6661.
These instructions are available on theInternet and in the [?] menu in TROVISVIEW.

Note
All parameter settings and configurations
must also be downloaded onto the positioner
before they can become effective.

Tip
The [Find...] function in the menu bar can beused to search for parameters:

8

EB 8389-2 ENStart-up

2.2 On-site operation

3 Start-up

Some parameters can be changed at the positioner as well as using the software. Referto the mounting and operating instructions of
the TROVIS 3793 Positioner (u EB 8493) fora list of all parameters that can be changed
locally at the positioner.

The positioner must be initialized to use thefull scope of the valve diagnostics. Duringinitialization, the positioner adapts itself optimally to the friction conditions and the signal pressure required by the control valve.
The positioner can be initialized using one of
the following initialization modes: MAX,NOM or MAN. Not all of the functions of
EXPERTplus can be used when a positioner
has been initialized in the SUB mode.

A password can be activated to prevent onsite access to the positioner settings without
prior consent. After the password has been
activated, the positioner settings can only bechanged on site after entering the password
at the positioner.
Note
We recommend:− Changing the password before first use.
− Keeping the password in a safe placeinaccessible to unauthorized persons.
− Only passing on the password toauthorized persons.
TROVIS 3793 > Configuration− Activate password: [Not active], Active− Modify password: 0000 to 9999, [1234]

1. Connect the positioner to the configuration and operating software.
Î The TROVIS-VIEW software on acomputer can be connected to thepositioner using an isolated USB interface adapter (order no. 14009740).
2. Check and compare the options installedin the positioner with the software.
Various options can be installed or retrofitted in the TROVIS 3793 Positioner (seethe Mounting and Operating Instructions
u EB 8493).
Î Check the parameter settings andstatus of the options (see Table 1).
3. Put the positioner into operation as described in the Mounting and Operating
Instructions u EB 8493.
We recommend using the following settings:− Positioners with pneumatic module
combination P3799-0001 andP3799-0000 or pneumatic module
combination P3799-0003 andEB 8389-2 EN

9

Start-up

P3799-004: the air output capacityof the software restriction is automatically adapted to the actuator size
when the 'Automatic software restriction setting' function is activated.
TROVIS 3793 > Start-up− Automatic software restriction setting:[Active]− Initialization with valve signature ensures that the full diagnostic functions
are available when the positioner isfitted with pressure sensors.
TROVIS 3793 > Start-up− Init. with valve signature: [Yes]When initialization fails, the positioner
generates a status message with the assigned status classification. See section 5.
If a status message is generated duringinitialization, the group status 'Start-up'
and 'Initialization' are also generated
with the assigned status classification.
See section 5.
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− Start-up:, , , , , [Highest classification]− Initialization:, , , , , [Highest classification]− Init: incorrect operating mode: [ ], , ,,− Init: travel too small: , [ ], , ,− Init: rated travel not achieved:, [ ], , ,10− Init: pin position: , [ ], , ,− Init: no movement: , [ ], , ,− Init: canceled (control accuracy): , , ,, , [highest classification]− Init: low control accuracy: , , , ,, [highest classification]− Positioner not initialized: , , [ ], ,− Init: canceled externally:

,[

],

,

,

− Init: angle limitation:, , , , , [highest classification]− Init: timeout:, , , , , [highest classification]
TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− Start-up− Initialization− Init: incorrect operating mode
− Init: travel too small− Init: rated travel not achieved− Init: pin position− Init: no movement− Init: canceled (control accuracy)− Init: low control accuracy− Positioner not initialized− Init: canceled externally− Init: angle limitation− Init: timeout

4. Read out positioner data.
Î In TROVIS-VIEW: select menu [Device> Read].

EB 8389-2 ENStart-up

3.1 Signal pressure limitation
Requirements for the use of the 'Signal pressure limitation' function:− The 'Pressure sensors' option is installedin the positioner (see nameplate and Table 1).
The pressure limitation ensures that the pressure in the actuator does not exceed the
maximum permissible pressure for the actuator.
The tight-closing function must be activated('Lower end position' parameter = "Active")to allow the signal pressure limitation to
work.
TROVIS 3793 > Start-up− Pressure limit: 2.5 to 10 bar [7.0 bar]
TROVIS 3793 > Configuration > Set point
processing− Lower end position: [Active]

Table 1: Required parameter settings for options and modules
Options and modules

Parameter settings for fullfunctionality

Comments

Pressure sensors

TROVIS 3793 > Configuration >Slot options > Pressure sensors

The pressure sensors option isnecessary to use the following
diagnostic functions:− Signal pressure limitation(see section 3.1)
− Course of supply pressure(see section 6.2)
− Valve signature (seesection 6.4)

− Pressure sensors exist: Yes

EB 8389-2 EN

11

Start-up

Options and modules

Parameter settings for fullfunctionality

Comments

Module with software switches
NAMUR (Z3799 Module [N])Module with hardware
inductive switches NAMUR(Z3799 Module [P]) 2)
Module with hardware
switches SPDT (Z3799 Module[M]) 2)Ext. position sensor (ohm)(Z3799 Module [E]) 1) 2)

TROVIS 3793 > Configuration >Slots options

Deactivation module (Z3799
Module [V])− Status Z3799 C/D: module
active− Identification: see 'Options andmodules' column

Analog feedback module(Z3799 Module [T])Module with binary input andleakage sensor (Z3799
Module [L])

Binary input and output(Z3799 module [U])Analog input 4 to 20 mA(Z3799 Module [A])1)

Additionally:

TROVIS 3793 > Configuration >Slots options− External position sensor status:
Option active
2)

The module with binary input
and leakage sensor isnecessary to use the leakage
sensor diagnostic function(see section 6.5).

The option module can only be
installed in Slot D.

Deactivation module and limit
switches (Z3799 Module [F]) 2)
Ext. position sensor mA(Z3799 Module [Y]) 1) 2)
Module with software limit
switches PLC no Ex. (Z3799
Module [X])
Pneumatic module A/B

TROVIS 3793 > Configuration > Pneumatic modules− P3799 A/B: Status: module active− Identification: Double-acting, Single-acting OUTPUT
138, Single-acting OUTPUT 238, Fail-in-place
module12

EB 8389-2 EN

Configuration

4 Configuration

TROVIS 3793 > Diagnosis/maintenance >Configuration

4.1 Limits− Total valve travel:
1000 to 90,000,000, [1,000,000]

The limits for the generation of status messages can be configured in the [Configuration] folder.
Pressure sensors
Limit only displayed when the positioner isfitted with the optional pressure sensors (seeTable 1):− 'Lower press. limit'
The 'Low supply pressure' status message
is generated with the assigned statusclassification when the supply pressure
falls below the lower pressure limit.
TROVIS 3793 > Diagnosis/maintenance >Configuration− Lower press. limit: 0.01 to 10.00 bar,
[2.50 bar]** The 'Lower press. limit' parameter is automatically recalculated on plotting the valve
signature.

Stress factor
The stress factor range is directly linked to
the load cycle histogram. See section 6.1.4.
Total valve travel− 'Total valve travel limit'
The 'Total valve travel' status message is
generated when the total valve travel exceeds the limit.

Set point deviation− 'Lag time for set point deviation':
The lag time is determined during initialization. It is the criterion to generate the'Set point deviation' status message.
A transit time of less than 180 s determined during initialization causes the'Lag time of set point deviation' to be set
to 30 s. A transit time of 180 s or moredetermined during initialization causes
the 'Lag time of set point deviation' to be
set to six times the transit time.
− 'Tolerance band for set point deviation+/-':
A set point deviation is recognized as asystem deviation when the valve position
deviates from the set point by the value
entered in this parameter.
TROVIS 3793 > Diagnosis/maintenance >Configuration− Tolerance band for set point deviation +/-:
0.1 to 10.0 %, [5.0 %]Logging− 'Log all classifications'
When 'Yes' is selected, messages with
'No message' classification are also
logged.
TROVIS 3793 > Diagnosis/maintenance >Configuration− Log all classifications:[Yes], No

EB 8389-2 EN13

Configuration

4.2 Status classification
A status classification is assigned to the status messages of the EXPERTplus valve diagnostics. This assigned status appears when astatus message is generated.

Status classification from low to high

The following classifications are possible:

14−

No message
If an event is classified as “No message”, this event does not have any
affect on the condensed state.

−

Maintenance required
The positioner still performs its control task (with restrictions). A maintenance demand has been determined.
The wear tolerance will soon be exhausted or is reducing at a faster rate
than expected. Maintenance is necessary in the medium term.

−

Out of specification
The positioner is operating outside
the specified operating conditions or
has not yet been initialized.

−

Function check
Test or calibration procedures are
performed in the positioner. The positioner is temporarily unable to perform its control task as long as theprocedure is taking place.

−

FailureThe positioner cannot perform its
control task due to a malfunction in
the positioner itself or in one of its
peripherals.

− Highest classification
Status classification of a group status(see section 5.2.1). The group status depends on the status classification assigned to the status messages: the status
message with the highest classification
determines the group status.
Note
In the 'On-site' user level, the active status messages are visible. In some cases,
only the active group status is visible
without the assigned status messages.
The status classification is predetermined inthe [> Diagnosis/maintenance > Configuration > Status classification] folder. All status
messages are assigned to a status by default.
Any generated error messages in positioners
with a binary output configured as a fault
alarm output are assigned the 'Failure' status. In addition, error messages generated
over the fault alarm output can also be configured to appear with the condensed state'Function check' and/or 'Maintenance required' and 'Out of specification'. In thiscase, the corresponding parameters must be
set (see Annex A (configuration instructions)).
Note
The 'Out of specification' status is assigned
to a positioner that has not yet been initialized.

EB 8389-2 EN

Configuration'Reset (standard)''Reset (advanced)'

Reset statusclassification'Reset diagnosis'

Reset
Initialization

4.2.1

No

No

No

YES

Fig. 1: > Diagnosis/maintenance > Configuration

EB 8389-2 EN

15

Device state

5 Device state

Temperature

5.1 Information parametersTime

The [Device state] folder contains information
parameters on the positioner state.

− 'Operating hours counter'

Pressure sensors
Information parameters only displayedwhen the positioner is fitted with the optional pressure sensors (see Table 1):− See section 5.4 for [Temperature] folder.

− 'Device switched on since last initialization'− 'Device in closed-loop operation'− 'Device in closed-loop operation sincelast initialization'− 'OUTPUT 138: pressure':
current pressure at output 138

Counter− 'OUTPUT 238: pressure':
current pressure at output 238− 'Number of zero calibrations'

5.1.1

Reset
'Reset (advanced)'− 'Max. supply pressure':highest supply pressure'Reset (standard)'− 'Time stamp for min. supply pressure'
Time at which the pressure displayed in'Min. supply pressure' occurred− 'Diagnostic data'
The diagnostic data are saved in a
non-volatile memory (EEPROM). Data
can be saved manually by the 'Save diagnostic data' command.

'Reset diagnosis'− 'Min. supply pressure':
lowest supply pressure

Save

Initialization− 'Supply pressure':
current supply pressure− 'Number of initializations'

Reset information
parameters without
operating hours
counter

YES

NO

YES

YES

Reset operating hours
counter

NO

NO

NO

NO

1)

YES

YES

YES

− 'Time stamp for max. supply pressure'
Time at which the pressure displayed in'Max. supply pressure' occurredStress factor
The stress factor range is directly linked to
the load cycle histogram. See section 6.1.4.
Total valve travel− 'Total valve travel':
Totaled full valve travel cycle

Reset limits
1)

16

Reset depending on limit

EB 8389-2 ENDevice stateFig. 2: > Diagnosis/maintenance > Device state

EB 8389-2 EN

17

Device state

5.2 Status messages
The valve diagnostics integrated into the positioner generate classified status messages.
All status messages with their assigned status
are listed in the [> Diagnosis/maintenance >Device state > Status classification] folder.

Tip
The condensed state is indicated on theright-hand corner of the status bar in
TROVIS-VIEW.

5.3 Logging

Note
The '
No message' status is generated
when:− The conditions to generate a status message are not fulfilled.
− The conditions to generate a status message are fulfilled, but the status message isassigned the 'No message' status.

EXPERTplus can log up to 400 events. They
are listed in the [> Diagnosis/maintenance >Device state > Logging] folder together withadditional information on the event and thetime it occurred.

Î We recommend following the recommended action listed in section 8 when astatus message occurs.

− The positioner was started up.

5.2.1

Group and condensed
statesTo provide a better overview on the individual status messages, various status messages
are summarized in a group status. If a status
message assigned to a group is active, thegroup status is generated according to thepredefined status classification.

Logging starts automatically. It does notneed to be activated by the user.
The following events are logged:− The positioner was successfully initialized.
− EXPERTplus generates a status message.
− A generated status message has beencanceled.
− A test was successfully completed.
Tip
Use [Find...] function to find a certain event:The condensed state is summary of all status
messages. To provide a better overview on
the condition of the valve, all status messages are summarized in a condensed state
which is made up from a summary of allclassified messages in the positioner. The status message with the highest priority determines the condensed state.

18

EB 8389-2 ENDevice stateFig. 3: > Diagnosis/maintenance > Device state > Logging

EB 8389-2 EN'Reset diagnosis''Reset (standard)''Reset (advanced)'

Reset logging'Reset logging'

Reset

Initialization

5.3.1

NO

YES

NO

YES

YES

19

Device state

5.4 Temperature

5.4.1

Reset
'Reset (advanced)'− 'Max. temperature inside device':
the highest temperature inside the device
while in service

Reset temperature
values'Reset (standard)'− 'Min. temperature inside device':the lowest temperature inside the device
while in service'Reset diagnosis'− 'Temperature inside device':current temperature inside the device

Initialization

The temperature inside the device is displayed:

YES

NO

NO

YES

− 'Minimum temperature limit':
The 'Temperature inside device below
min. limit' status message is generated
with the assigned status classification
when the temperature inside the device
falls below the limit. The status message
is cleared as soon as the temperature rises above the limit again.
− 'Maximum temperature limit':
The 'Temperature inside device above
max. limit' status message is generated
with the assigned status classification
when the temperature inside the device
exceeds the limit. The status message iscleared as soon as the temperature falls
below the limit again.
Note
The 'Minimum temperature limit' and 'Maximum temperature limit' parameters are set to–60 °C and 80 °C respectively by default.
These settings can only be changed in the'Customer expert' user level.

20

EB 8389-2 EN

Statistical information

Data logging and analysis do not need to be
activated.
EXPERTplus has histograms on the following
topics:− Valve position (see section 6.1.2)− Set point deviation (see section 6.1.3)− Load cycle (see section 6.1.4)
The histograms can be displayed for different monitoring periods. The monitoring periods are indicated on the horizontal coordinate axis. By default, the entire valve life cy-

EB 8389-2 EN− Years (setting range: [This year], Last
year, Year before last, Three years ago,…, Five years ago)

6.1.1

Reset

The valve position, set point deviation andload cycle histograms are all reset. It is notpossible to reset single histograms.
'Reset (advanced)'

Tip
Data can also be saved manually by thecommand 'Save diagnostic data' in the[Diagnosis/maintenance > Device state]folder.

− Months (setting range: [This month], Lastmonth, Month before last, Three months
ago, …, Eleven weeks ago)

'Reset (standard)'

Histograms are a statistical analysis. The
tests for the histograms are performed by the
positioner automatically in the AUTO andSAFE modes. For this purpose, data arelogged every second and saved in a
non-volatile memory every 24 hours.

− Weeks (setting range: [This week], Last
week, Week before last, Three weeks
ago)'Reset diagnosis'

6.1 Histograms− Days (setting range: [Today], Yesterday,
Day before yesterday, Three days ago,…, Six days ago)

'Reset histograms'

The Statistical information compiles data
while the process is running without
disrupting the process. The data are saved
and analyzed in the positioner, i.e. thepositioner follows the set point to position thevalve. A classified status message is
generated when the positioner detects anevent.

cle is shown in the histogram. Other possible
settings include:

Initialization

6 Statistical informationResetmeasured data

YES

YES

YES

YES

YES

Reset archived
data

YES

YES

YES

YES

YES

Status messages generated as a result of thehistogram analysis cannot be cleared
manually. They are automatically cleared assoon as the conditions that caused the status
messages to be generated no longer prevail.

21

Statistical information

6.1.2

Valve position

The valve position histogram provides information about the range in which valve mainly works during its service life and whether
the operating range is possibly shifting.
The positioner records the valve position every second and arranges the data in predefined valve position classes. The distribution among the valve position classes isshown in a bar graph.
Analysis and monitoring
The first and last class indicate how often the'End position w ≤' and 'End position w ≥'functions have been triggered.

− The 'End position w ≥' function causes
the valve to move to the maximum open
position when the valve position reaches
an adjustable set point.
The functions can be adjusted in the[> Configuration > Set point processing]folder.
A valve position that is mainly located close
to the closed or maximum open position pinpoints to a valve that is too large or too
small.
Î We recommend checking the valve
sizing.

− The 'End position w ≤' function causes
the valve to move to the closed position
when the valve position reaches an adjustable set point.

Fig. 4: > Diagnosis/maintenance > Statistical information > Histograms > Valve position

22

EB 8389-2 EN

Statistical information

6.1.3

Set point deviation

The set point deviation histogram provides
information on to which extent a set point
deviation has occurred and whether faults
may occur due to a restricted working range.
The positioner records the set point deviation
every second and arranges the data in predefined classes. The distribution among theset point deviation classes is shown in a bar
graph.
Analysis and monitoring
Ideally, the set point deviation should be as
close to 0 % as possible.
Set point deviations greater than 1 % occurring within a short span of time pinpoint to alimitation of the upper working range.

Î We recommend checking the attachment.
Set point deviations smaller than 1 % occurring within a short span of time pinpoint to alimitation of the lower working range or toseat leakage.
Î We recommend checking the attachment
as well as the seat and plug for wear.
If almost all set point deviations during theshort-term monitoring are greater than 1 %or smaller than –1 %, this may indicated thatthe actuator or valve stem is jammed.
Î We recommend checking the plug stem
for external influences that could beblocking it.

Fig. 5: > Diagnosis/maintenance > Statistical information > Histograms > Set point deviation

EB 8389-2 EN

23

Statistical information

6.1.4

Load cycle

The load cycle histogram provides a statistical analysis of the cycles that the valve has
moved through. As a result, the cycle counter
also provides information on the dynamic
stress of a bellows seal and/or packing.
The positioner records the height of the cycles that the valve has moved through taking
the selected stem seal into account.
The cycles are assigned to classes. The distribution showing how often the cycle occurred
within a class is shown in a bar graph.
TROVIS 3793 > Diagnosis/maintenance >Device state! NOTICE
No analysis of 'Dynamic stress factor' with
'Stem seal' = "Not selected" (= default setting).
Î Set 'Stem seal' parameter to allow ananalysis of the load cycle histogram tobe performed.
Analysis and monitoring
The load on the bellows and/or packing canbe read from the 'Dynamic stress factor' parameter. The value is determined from the cycle spans or cycle heights and takes into account the type of packing used in the valve.

− Stem seal: [Not selected], Self-adjusting, Adjustable, Bellows, Other− Max. cycle count:
1 to 1000000000, [1000000]

A valve cycle span starts at the
point where the valve strokechanges direction until the
point where it changes
direction again.

x [%]
1

3

2

4
t [s]

Fig. 6: > Diagnosis/maintenance > Statistical information > Histograms > Load cycle24

EB 8389-2 EN

Statistical information

A 'Dynamic stress factor exceeded' status
message is generated with the assigned status classification whenever:Î We recommend checking the conditionof the packing when the status message
is generated to prevent external leakage.

− The number of measured cycle spans
exceeds 2,000,000 when 'Self-adjusting'is selected as the stem seal.

6.2 Course of end position− The number of measured cycle spans
exceeds 800,000 when 'Adjustable' isselected as the stem seal.
− The number of measured cycle spans
exceeds 90 % of the 'Max. cycle count'when 'Other' is selected as the stem seal.
− The number of measured cycle heights
exceeds 8473930 when 'Bellows' isselected as the stem seal.
Tip
The level of stress that the packing is subjected to depends on other factors besides load
cycles, e.g. on the process medium and theoperating conditions. Therefore, in the 'Customer expert' user level, it is possible toadapt the limits to trigger the 'Dynamic stressfactor exceeded' status message as required.
TROVIS 3793 > Diagnosis/maintenance >Device state− Dynamic stress factor
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− Dynamic stress factor exceeded:, [ ], , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− Dynamic stress factor exceeded

EB 8389-2 EN

Data are recorded in the backgroundregardless of the operating mode selected
when the conditions for logging data are
fulfilled (see sections 6.2.1 and 6.2.2). Data
logging does not need to be activated.
The course of end position function records
the measured data when the valve moves tothe end position:− Valve position− Temperature− Time stamp of operating hours counter
The new recorded end position is comparedto the last saved end position. If the valve
position deviates from the last value by
0.3 %, the data of the new end position are
saved.
A graph of the recorded end positions isplotted over time.
The positioner saves the valve positions in acircular buffer, which holds 30 measured
values at one time.
Analysis and monitoring
The 'Course of lower end position' and'Course of upper end position' status
messages are generated with the assigned
status classification whenever a newrecorded end position deviates from thereference value by the 'Threshold for end
position shift'. The reference value isdetermined during initialization (see25Statistical information

sections 6.2.1 and 6.2.2). It is shown as astraight line in the graph.
TROVIS 3793 > Diagnosis/maintenance >Statistical information > Course of end position

The reference value for the course of the lower end position is reference zero. This is determined during a MAX or NOM initialization and during a zero calibration.

− Threshold for end position shift:
0.3 to 100.0 %, [5.0 %]TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification

Note
When temperature fluctuations occur andwith valves with a long insulating section, the'Course of lower end position' and 'Courseof upper end position' status messages may
be generated at an early stage.

6.2.1

Course of lower end
position

To record data for the course of lower end
position (behavior while the valve is in thetight shut position), the following conditions
must exist:− The positioner was initialized in the MAX
or NOM mode.
− The tight-closing function is active ('Lower end position' parameter = "Active").
TROVIS 3793 > Configuration > Set point
processing− Lower end position: [Active]

Note
When the end position function is active, thevalve shuts off tightly as soon as the set point
is lower or equal to the value entered in 'End
position w <='.

26

− Lower end position shifted:, [ ], , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− Lower end position shifted

The generation of the 'Lower end position
shifted' status message in combination witha shift of the course of the end position
downward pinpoints to signs of wear between seat and plug in metal-seated valves.
Î We recommend checking the seat andplug for wear.
Note
The 'Lower end position shifted' status message is generated briefly after the initialization of soft-seated valves for design reasons.
The soft seal settles after a few load cycles
causing zero to be shifted. In these valves, a
repeated generation of the status message
after a long time service first indicates signs
of wear.
The generation of the 'Lower end position
shifted' status message in combination witha shift of the course of the end position upward pinpoints to a blockage of the plug
stem, e.g. due to dirt particles.
Î We recommend checking the plug stem
for mechanical blockage.
EB 8389-2 EN

Statistical information

6.2.1.1 ResetTROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification

See Table 2

6.2.2

Course of upper end
position

The positioner must be initialized in the MAX
mode to allow the course of end position
data to be recorded.

− Upper end position shifted:, [ ], , ,> Diagnosis/maintenance > Device state >Status messages− Upper end position shiftedÎ We recommend checking the plug stem
for mechanical blockage when the status
message is generated.

The reference value for the course of the upper end position is the travel at the maximum
open valve position. It is determined only in
the MAX initialization mode.

6.2.2.1 Reset

Analysis and monitoring

See Table 2

If the analysis of the course of the upper end
position pinpoints to a fault, the positioner
generates the 'Upper end position shifted'
status message with the assigned status classification.

Initialization

Zero calibration'Reset course of end
position''Reset diagnosis''Reset (standard)''Reset (advanced)'

Table 2: Reset the course of end position

Reset reference Lower end position
value
Upper end position

YES

YES

NO

NO

NO

NO

YES

NO

NO

NO

NO

NO

Reset
measured
data

Lower end position

NO

NO

YES

YES

YES

YES

Upper end position

NO

NO

YES

YES

YES

YES

Lower end position

YES

YES

NO

YES

YES

YES

Upper end position

YES

NO

NO

YES

YES

YES

Reset status
messageEB 8389-2 EN

27

Statistical information

Fig. 7: > Diagnosis/maintenance > Statistical information > Course of lower end position

Fig. 8: > Diagnosis/maintenance > Statistical information > Course of upper end position

28

EB 8389-2 EN

Statistical informationResetmeasured data

'Reset (advanced)'

TROVIS 3793 > Diagnosis/maintenance >Statistical information > Course of supply
pressure'Reset (standard)'

The supply pressure is recorded in the background, regardless of the operating mode
selected, if the current supply pressure deviates from the last recorded value in the diagram by the amount specified in 'New recording threshold for supply pressure'. Data
logging does not need to be activated.

'Reset diagnosis'

Reset'Reset course of supply
pressure'

6.3.1

Initialization

6.3 Course of supply pressure

NO

YES

YES

YES

YES

− New recording threshold for supply pressure:
0.10 to 5.00 bar, [1.00 bar]

Fig. 9: Diagnostics > Monitoring/tests > Valve signature > Course of supply pressure

EB 8389-2 EN

29

Statistical information

6.4 Valve signature
Requirements for the use of the 'Valve signature' diagnostic function:
The 'Pressure sensors' option is installed in
the positioner (see nameplate and Table 1).

TROVIS 3793 > Configuration >Identification > Actuator− Principle of operation: Single-acting− The positioner was successfully initialized
in the MAX, NOM or MAN mode.

Valve signature (statistical information) only
possible when the positioner is fitted withthe optional pressure sensors.

6.4.1

The valve signature records the signal pressure during the supply and exhaust process
in relation to the valve position. It also determines lower and upper bench range values.

During the plotting of the reference graph(Fig. 10), the valve is moved from the unpressurized end position until it is close to
the maximum open position and back again.
To perform this function, the pneumatic modules switch to open-loop control (control
without feedback).

All diagnostic functions dependent on thesignal pressure are based on the valve signature.
Test requirement− A single-acting actuator is mounted on
the valve.

Recording referencegraphsAfter the reference graph has been plotted,
the recorded values for 'Pressure (supplyair)', 'Pressure (exhaust)' and the valve position are converted into fixed points.

Fig. 10: > Diagnosis/maintenance > Statistical information > Valve signature30

EB 8389-2 EN

Statistical information

Recording the reference graph

Analysis and monitoring

The reference graph is automatically plotted
after initialization when 'Init. with valve signature' = Yes.

The positioner records the supply and exhaust data and plots their lines in a graph. It
then determines the characteristic values listed below:

TROVIS 3793 > Start-up− Init. with valve signature: [Yes]If a reference graph does not exist, the reference test can be started manually.
1. Switch to MAN mode.
The 'Operating mode not AUTO' status
message is generated based on its set
status classification.
TROVIS 3793
− Target operating mode: MAN

2. Start recording of reference graphs.
The 'Progress' reading shows the progress of the plotting of the reference graphin %.
'Function check'is activated as thecondensed state.
TROVIS 3793 > Diagnosis/maintenance >Statistical information > Valve signature! Start reference− Progress
Note
The plotting of the reference graph can beinterrupted by the 'Stop test' parameter orby pressing the rotary pushbutton. This may
be necessary when the test takes too long,e.g. control valves with large actuators.
After the reference graph has been plotted,
the positioner remains in the MAN mode.

EB 8389-2 EN− 'Average hysteresis': average hysteresis(average signal pressure difference inrelation to the spring range)− 'Min. hysteresis': lowest possible
hysteresis (minimum signal pressure
difference in relation to the spring range)− 'Max. hysteresis': highest possible
hysteresis (maximum signal pressure
difference in relation to the spring range)− 'Detected lower spring range value':
Signal pressure pout at minimum supply− 'Detected upper bench range value':
Signal pressure pout when the actuator at
maximum supply
The 'Valve signature canceled' status message is generated with the assigned status if
the reference recording is canceled. A detailed description on the reasons for cancellation can be found in the 'Result of lastvalve signature' parameter.
The 'Valve signature status' parameter is set
to 'Invalid' when not enough values havebeen recorded or the exhaust line is partly
above the supply line in the graph. In thiscase, the measurement is not assessed.
TROVIS 3793 > Diagnosis/maintenance >Statistical information > Valve signature− Valve signature status: Valid, Invalid− Result of the last valve signature: Not executed,
Successful, Canceled (man.) etc.

31

Statistical information

Analysis and monitoring

TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− Valve signature failed:, [ ], , ,The positioner monitors the supply pressureand generates one of the following status
messages in case of an incident:

TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− 'No supply press.' if the supply pressure
falls below 0.1 bar.

− Valve signature failed− 'Low supply pressure' if the supply pressure is below 'Lower press. limit', but
above 0.1 bar.

Note
The valve signature can be recorded again
at any time and compared with the reference(see section 7.4) to assess the valve performance.

6.4.2

The status messages are cleared when the
supply pressure falls below or exceeds thepressure limit again.
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification

Initialization'Reset diagnosis''Reset (standard)''Reset (advanced)'

6.4.1.1 Reset

Reset status message− 'Supply pressure > 10 bar'

YES

YES

YES

YES

Monitoring

The positioner records the signal pressure(monitoring diagram) during closed-loop operation. It is compared with the referencegraph. Additionally, the minimum, maximum
and current supply pressure are shown in thegraph.

− No supply press.: , , [ ], ,− Low supply pressure: , [ ], , ,− Supply pressure > 10 bar: , , [ ],,TROVIS 3793 > Diagnosis/maintenance > Device state > Status messages− No supply pressure− Low supply pressure− Supply pressure > 10 bar

Î We recommend checking the supply
pressure, supply pressure regulator andpneumatic connections after a status
message has been generated.

Data are recorded in the background regardless of the operating mode selected if areference graph has already been plotted.
Data logging does not need to be activated.

32

EB 8389-2 EN

Statistical information

Initialization'Reset diagnosis''Reset (standard)''Reset (advanced)'

6.4.2.1 Reset

Reset measured data(monitoring)

YES

YES

YES

YES

Reset status messages

YES

NO

NO

NO

6.4.3

Friction

The positioner calculates the friction duringclosed-loop operation and compares it withthe friction determined when the referencegraph was plotted.
Data are recorded in the backgroundregardless of the operating mode selected
provided a reference graph has alreadybeen plotted. Data logging does not need tobe activated.
Analysis and monitoring

If the friction at a fixed point increases tomore than double of the reference friction,
the friction is regarded to be higher.
If the friction at a fixed point drops to lessthan half of the reference friction, the friction
is regarded to be lower.
Note
The valve must not move too quickly. Otherwise, it is not possible to compare the calculated friction with the reference friction.
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− Friction change (open pos.):

,[

],

,

,

− Friction change (mid-pos.): , [ ], , ,− Friction change (closed pos.): , [ ], , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− Friction change (open pos.)− Friction change (mid-pos.)− Friction change (closed pos.)

The friction for the total range of the valve,the mid valve position and for the ranges
near to the closed position are compared.
The positioner calculates the friction duringclosed-loop operation from the plotted supply and exhaust lines at the point where a
directional change in valve travel takes
place. The positioner converts the friction data into fixed points close to the point of directional change and compares them to thereference friction.

EB 8389-2 EN

33

Statistical information

Fig. 11: > Diagnosis/maintenance > Statistical information > Valve signature > Monitoring

Fig. 12: > Diagnosis/maintenance > Statistical information > Valve signature > Friction

34

EB 8389-2 EN

Statistical information

6.5 Leakage sensor
Leakage sensor (statistical information) only
possible when the positioner has a mounted
external leakage sensor (option module L).
By upgrading the positioner with a leakage
sensor, it is possible to detect seat leakage
when the valve is in the closed position. For
this purpose, the leakage sensor amplifies
the noise level in the tight shut position to detect increased seat leakage.
Requirements for using the seat leakage
detection:
1. A leakage sensor is mounted on thevalve (see the mounting and operating
instructions of the positioner
u EB 8493).
2. The option module L (Z3799-xxx70) is
installed in the positioner (see Table 1).
3. The tight-closing function is activated.
TROVIS 3793 > Diagnosis/maintenance >Statistical information > Leakage sensor
2.

− Leakage sensor status: Option active
TROVIS 3793 > Configuration > Set point
processing

3.

− Lower end position: [Active]− End position w <= 0.0 to 49.9 %, [1.0 %]buffer that holds 30 measured values at one
time together with a time stamp.
TROVIS 3793 > Diagnosis/maintenance > Statistical information > Leakage sensor− Recording threshold: 3 to 255 dB, [5 dB]

Analysis and monitoring
The 'Leakage: level limit 1 exceeded' alarmis generated with the assigned status classification when the level in the tight shut position exceeds the 'Threshold alarm 1'. The'Leakage: level limit 2 exceeded' alarm isgenerated accordingly when the level exceeds the 'Threshold alarm 2'.
TROVIS 3793 > Diagnosis/maintenance >Statistical information > Leakage sensor− Threshold alarm 1: 3 to 255 dB, [30 dB]− Threshold alarm 2: 3 to 255 dB, [40 dB]
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− Leakage: level limit 1 exceeded:, [ ], , ,− Leakage: level limit 2 exceeded:, [ ], , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− Leakage: level limit 1 exceeded− Leakage: level limit 2 exceeded

Data are recorded in the background regardless of the operating mode selected. Data logging does not need to be activated.
The leakage sensor records the sound level
when the valve leaves the tight shut position
or whenever the sound level changes by the'Recording threshold' value. The positioner
saves the sound level values in a circular

EB 8389-2 EN

35

Statistical information

Initialization'Reset diagnosis''Reset (standard)''Reset (advanced)'

6.5.3.1 Reset

Reset measured data

NO

YES

YES

YES

Reset status messages

NO

YES

YES

YES

Fig. 13: > Diagnosis/maintenance > Statistical information > Valve signature > Leakage sensor

36

EB 8389-2 ENTests7 Tests
Similar to the statistical information, data arecompiled, saved and analyzed in thepositioner for the tests. However, in thiscase, the valve position is not determinedby the set point, but by the active test. The
tests can only be started when the conditionsin the plant allow it (e.g. plant shutdown orservice work in the workshop). For reasonsof safety, the tests, except for partial stroke
testing, can only be performed in the MAN
operating mode.
Note
An active test is stopped and the positioner
changes to the fail-safe position when theelectrical signal falls below a certain level orwhen the forced venting function is triggered.

7.1 Partial stroke test (PST)Note
In older software versions, the term "stepresponse test (SRT)" was used in place of"partial stroke test (PST)". The terms aresynonymous and are used to describe thesame test.
The partial stroke test (PST) is particularly
suitable for the status-oriented detection of
malfunctions in pneumatic shut-off valves. As
a result, the probability of failure on demand(PFD) can be reduced and it may be possible
to extend maintenance intervals. A shut-off

EB 8389-2 ENvalve normally in its end position can beprevented from seizing up or getting
jammed. The initial breakaway torque mustfirst be overcome after the valve starts tomove from its end position. The initial breakaway torque depends on the plug/seat seal,
deposits on the plug, the process medium
and friction at the valve trim. After the initial
breakaway torque has been overcome, it
can be assumed that the valve is able toclose completely. The recording of the test results additionally allows an analysis of the
dynamic control response.
During the partial stroke test, the valve
moves from its current operating point by adefined change in travel and back to theinitial position again. The change in travel iscalculated from the 'Start value' and 'Stepheight'.
The change in travel can be performed either in steps or in a ramp function (Fig. 14).
The test is performed with the ramp function
when the ramp times ('Ramp 1' and 'Ramp2') are set to ≠ 0 s.
The test starts after reaching the 'Start value'
and the 'Delay time' has elapsed. Startingfrom the 'Start value', the valve moves
through the 'Step height' in the 'Test
direction'. The valve remains in this position
for the time defined in 'Delay time' before
performing a second step change in the
opposite direction to the operating point. The'Sampling time' defines the time interval
between which the measured values arerecorded during the test.

37

TestsTROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST) > Configuration

TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration− Start value: –20 to 120 %, [100 %]− Step height: 2 to 100 %, [10 %]− Test direction: [Minus], Plus
− Ramp 1: 0 to 9999 s, [60 s]− Ramp 2: 0 to 9999 s, [6 s]− Sampling rate (not write-enabled)

7.1.1

Test cancellation criteria

Various test cancellation conditions provide
additional protection against the valve slamming shut or moving further than the stepheight. The positioner cancels the partial
stroke test when one of the following cancellation conditions is fulfilled:− Canceled: max. test duration (not writeenabled)− 'Canceled: max. dead time': the test iscanceled when the 'Delay time' haselapsed without the valve having movedby the value 'Dead time limit determined'.
This cancellation criterion only takes effect when 'Dead time limit determined' is
set to ≠ 0 %.
TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration

Time− Canceled: max. dead time (not writeenabled)− Dead time limit determined: 1 to 10 %,[2 %]− 'Canceled: max. test duration': the test iscanceled when the maximum permissible
test duration calculated by the positioner
is reached.
Test start

Test start

Operatingpoint
Start value
Step height

2 x Start value
Tolerance band +/–

x [%]

Delay
time

Delay
time

t [s]

Delay
time

Delay
time
Ramp 1

Ramp 2

Fig. 14: Course of the partial stroke test with step response (left) and ramp function (right)

38

EB 8389-2 ENTestsTolerance bands− 'Start value of tolerance band +/–': thetest is not started when the operating
point is outside the range: 'Start value' ±'Start value of tolerance band +/–'.
TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration− Start value of tolerance band +/–:
1 to 100 %, [3 %]− 'Canceled: tolerance band (ramp) +/–','Canceled: tolerance band (step) +/–':The test is canceled as soon as the deviation of the valve position (in relation to
the theoretical step end value, calculated
from the 'Start value' and 'Step height')
exceeds the adjusted value.
This cancellation criterion only takes effect when 'Canceled: tolerance band(ramp) +/–' or 'Canceled: tolerance
band (step) +/–' is set to ≠ 0 %.
TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration− Canceled: tolerance band (step) +/–:
can only be selected in the 'Customer
expert' user level− Canceled: tolerance band (ramp) +/–:
1 to 100 %, [5 %]Valve position− 'Canceled: x monitoring': the test iscanceled when 'Minus' is selected as the'Test direction' as soon as the valve
position falls below the adjusted value.

EB 8389-2 EN

The test is canceled when 'Plus' isselected as the 'Test direction' as soon as
the valve position exceeds the adjusted
value.
This cancellation criterion only takes effect when 'Canceled: x monitoring' is set
to ≠ 0 %.
TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration− Canceled: x monitoring: –20 to 120 %,[ATO: 85 %; ATC: 15 %]Pressure criteria
Analysis of the pressure only possible when
the positioner is fitted with the optionalpressure sensors (see Table 1).
− 'Canceled (press. limit)': the test is canceled after the valve has moved to thetest end value through venting and thepressure is below this limit. The test iscanceled after the valve has moved to thetest end value through supplying air andthe pressure exceeds this limit.
This cancellation criterion only takes effect when the 'Activate pressure monitoring' is set to "Active".
Tip
The minimum or maximum pressure of
the reference test can be used as a guidefor the limit defined in 'Canceled (press.
limit)'. See section 7.1.3.

39

TestsTest start

Table 3: Start conditions of partial stroke test

AUTO

YES

YES

YES

MAN

YES

NO

YES

− The internal forced venting function istriggered.

7.1.2.1 Manual start− The current is lower than 3.8 mA.

On-site operation− The test is canceled manually:

Start triggered by the binary
input (see section 7.2.2.2)

The reason why the test was canceled can beread in the 'Results of last test' parameter.
Besides cancellation due to the configured
test cancellation criteria, further events leadto the test being canceled, for example:

7.1.2

Automatic start after 'Test
interval' has elapsed (seesection 7.1.2.2)

Notes on cancellation criteria− The partial stroke test must only be
performed with the cancellation conditions(time or valve position) for valves withdouble-acting actuator and pneumatic
booster as well as for valves that havebeen initialized using the SUB mode.
− Excessive overshooting may occur in valvesfitted with volume boosters. In this case, thetest cancellation criteria 'Canceled: xmonitoring' and 'Canceled: tolerance band(ramp) +/–' or 'Canceled: tolerance band(step) +/–' must be increased accordingly.

− In AUTO mode, the edge control changes to the state in which the valve moves
to a fixed value which is outside therange: 'Start value' ± 'Start value of tolerance band +/–'.

See section 7.1.2.1 formanual start (on site or using
software)− Activate pressure monitoring: Active− Canceled (press. limit): [0.00] to 10.00 bar− At the start of the partial stroke test triggered by the binary input, the edge control changes again to the state whichstarts the partial stroke test.

Operating mode

TROVIS 3793 > Diagnosis/maintenance >Tests > Partial stroke test (PST) >Configuration

Î On site by pressing the rotary pushbutton
Î In the software with the 'Stop test'
parameter− The positioner switches to the SAFE
mode.

40

EB 8389-2 ENTestsÎ Use the rotary pushbutton to go to the'Partial stroke test (PST)' command (menuitem: [10 Diagnosis/maintenance >Tests]). See u EB 8493.
Î Press

to start test.

Note
A test can be canceled manually by pressing
the rotary pushbutton again.
Software command via TROVIS-VIEW/
integration
TROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST)! Start test
Note
The test can be canceled manually by selecting the 'Stop test' command.

7.1.2.2 Automatic start after 'Test
interval' has elapsed
The partial stroke test (PST) is started in
AUTO mode at regular intervals after thetime entered in 'Test interval' has elapsed
when the function is activated. The 'Delaytime interval' parameter allows the test to be
postponed once.
Note
The time until the next regular test can beread in the 'Time until next test' information
parameter.

EB 8389-2 EN

TROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST) > Configuration− Test interval: 1 to 365 d, [7 d]− Activate test interval: [Not active], Active− Delay test interval: [0] to 2160 h
TROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST)− Time until next test (not write-enabled)

7.1.2.3 Start triggered by binary
input
Function only possible when positioners has
option module [T] or [V].
TROVIS 3793 > Configuration > Slots options >Slot C− Action upon active binary input: start PST− Edge control:[Active = switch closed], Active = switch open

7.1.3

Analysis and monitoring

The analysis of the last fifty partial stroke test
(PST) are saved with a time stamp in the [>Diagnosis/maintenance > Tests > Partial
stroke test (PST) > Reports and diagrams]
folder. The last seven graphs at the maximum
are shown.
The result of the last test can be read in the[> Diagnosis/maintenance > Tests > Partial
stroke test (PST)] folder.
Note
In total, seven stroke tests (PST plus FST) with
report and diagram can be displayed.

41

TestsTest completed successfully
The following analysis parameters are shown
after a completed partial stroke test (PST).
− Time stamp− Dead time: time from when the test starts
until the first measurable movement of
the valve.
− T98: time which the valve requires fromthe test start until it reaches 98 % of the
final value in the idle state.

− Overshooting range: overshoot in relation to the step height− Min. pressure: lowest pressure measured
during the test.
− Test status− Breakaway pressure: pressure required
to move the valve from the idle position
when the test starts

Fig. 15: > Diagnosis/maintenance > Tests > Partial stroke test (PST) > Reports and diagrams

42

EB 8389-2 ENTests− Time stamp (not write-enabled)− Dead time (not write-enabled)− T86 (not write-enabled)− Overshooting range (not write-enabled)− Min. pressure (ramp 1; exhaust)/max. pressure(ramp 1; supply) (only with pressure sensors)(not write-enabled)− Test status (not write-enabled)− Breakaway pressure

The results of the first partial stroke test performed with the current configuration areused as a reference and are write-protected.
All other partial stroke tests can be
write-protected manually:Î Checkbox.

Test not completed
If the test is canceled and no events have occurred that activate the fail-safe position, thepositioner changes to the 'Target operating
mode'.
The fail-safe position can be activated, forexample when the forced venting is triggered
and when the current is lower than 3.8 mA.
A test cancellation causes the 'PST: cancellation criteria met' status message to be generated with the assigned status classification.

TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− PST: cancellation criteria met:
, [ ], , ,− PST: start criteria not met:[ ], , , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− PST: cancellation criteria met− PST: start criteria not met

Table 4: Recommended action when the status message is generated
Test canceled

TROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST) > Reports anddiagrams

Note
No graph is plotted when a test cannot be
started.

Start criterion

Two test reports can be shown at one time
for comparison. The comparison test can beselected as required.

Test result

We recommend:

Current

Î Check input signal

Internal errorÎ Restart test

Timeout

Î Check seat and plugfor deposits or foreign
particles

No movement
possible
Start criteria

Î Check test configuration

Function
activeÎ Wait for the active test
to finish and restart
test.

Incorrect
operatingmodeÎ Set operating mode
corresponding to Table 3 and restart test.

If the test cannot be started, the 'PST: start
criteria not met' status message with the assigned status classification is generated.

EB 8389-2 EN

43

TestsStatistical analysis
Every time a partial stroke test is started, oneof the following counters counts this event
depending on the test status.
TROVIS 3793 > Diagnosis/maintenance > Tests> Partial stroke test (PST)− Number of successful tests (not write-enabled)− Number of canceled tests (not write-enabled)− Number of failed start criteria (not writeenabled)

7.1.4

Reset

See Table 5'Reset diagnosis''Clear reports''Reset (standard)''Reset (advanced)'

Reset configuration

Initialization

Table 5: Resetting the partial stroke test (PST)

NO

NO

NO

YES

YES

Reset reports

NO

YES

YES

YES

YES

Reset histograms

NO

YES

YES

YES

YES

Reset reference test

NO

YES

YES

YES

YES

Reset status messages

NO

YES

NO

YES

YES

44

EB 8389-2 ENTests

7.2 Full stroke test (FST)Note
In older software versions, the term "stepresponse test (SRT-100 %)" was used inplace of "full stroke test (FST)". The terms aresynonymous and are used to describe thesame test.
The dynamic control response can be evaluated by performing the test. During the fullstroke test (FST), the valve moves through its
entire working range.
The valve can move through the working
range either in steps or with a ramp function(Fig. 16). The test is performed with theramp function when the ramp time ('Ramp')
is set to ≠ 0 s.

Start value
Tolerance band +/–100

End value
Tolerance band +/–

x [%]

0

The test starts after the 'Delay time' haselapsed. This ensures that the valve hasreached the maximum open position.
Starting from the maximum open position,
the valve moves to the closed position. The
valve remains in this position for the time
defined by the 'Delay time' before
performing a second step change in the
opposite direction from the closed position to
the maximum open position. The 'Samplingtime' defines the time interval between which
the measured values are recorded during thetest.
TROVIS 3793 > Diagnosis/maintenance > Tests> Full stroke test (FST) > Configuration− Ramp 1: 0 to 9999 s, [60 s]− Delay time: 0 to 240 s, [2 s]Test start

Test start

Delay time

Delay
time

Delay
time

t [s]
Delay time
Ramp

Ramp

Fig. 16: Course of the full stroke test with step response (left) and ramp function (right)

EB 8389-2 EN

45

Tests

7.2.1

Test cancellation criteria

The positioner cancels the full stroke test
(FST) when one of the following cancellation
conditions is fulfilled:Time− 'Canceled: max. test duration': the test iscanceled when the maximum permissible
test duration calculated by the positioner
is reached.
TROVIS 3793 > Diagnosis/maintenance >Tests > Full stroke test (FST) > Configuration− Canceled: max. test duration (not writeenabled)

Tolerance bands− 'Start value of tolerance band +/–': thetest is not started if the operating point is
outside the range: maximum open position – 'Start value of tolerance band +/–'.

− The internal forced venting function istriggered.
− The current is lower than 3.8 mA.
− The test is manually canceled:Î On site by pressing the rotary pushbutton
Î In the software with the 'Stop test'
parameter− The positioner switches to the SAFE
mode.
− At the start of the full stroke test triggeredby the binary input, the edge control
changes again to the state which starts
the full stroke test (FST).

7.2.2

Test start− 'End value of tolerance band +/–': thetest is not started if the valve position after the first step does not reach therange: closed position + 'End value oftolerance band +/–'.

See section 7.2.2.1 formanual start (on site or using software)

Start triggered by binary
input (see section 7.2.2.2)

Table 6: Start conditions of full stroke test
(FST)

Operating mode

TROVIS 3793 > Diagnosis/maintenance >Tests > Full stroke test (FST) > Configuration

Additionally, the full stroke test (FST) is canceled when one of the following events arises:

TROVIS 3793 > Diagnosis/maintenance >Tests > Full stroke test (FST) > Configuration

AUTO

NO 1)

NO 1)

MAN

YES

YES

− Start value of tolerance band +/–:
1 to 100 %, [3 %]− End value of tolerance band +/–: 1 to
100 %, [3 %]46

1)Default setting
By activating the 'Allow start in AUTO mode'parameter in the 'Customer expert' user level,
the test can also be started in AUTO mode.

EB 8389-2 ENTests

7.2.2.1 Manual startOn-site operation

7.2.2.2 Start triggered by binary
input
Function only possible when positioners has
option module [T] or [V].
TROVIS 3793 > Configuration > Slots options >Slot CÎ Use the rotary pushbutton to go to the'Full stroke test (FST)' command (menuitem: [10 Diagnosis/maintenance >Tests]). See u EB 8493.
Î Press

to start test.

Note
A test can be canceled manually by pressing
the rotary pushbutton again.
Software command via TROVIS-VIEW/
integration
TROVIS 3793 > Diagnosis/maintenance > Tests> Full stroke test (FST)! Start test
Note
The test can be canceled manually by selecting the 'Stop test' command.

− Action upon active binary input: start FST− Edge control:[Active = switch closed], Active = switch open

7.2.3

Analysis and monitoring

The analysis of the last six full stroke test
(FST) at the maximum and graphs are savedwith a time stamp in the [> Diagnosis/maintenance > Tests > Full stroke test (FST) > Reports and diagrams] folder.
The result of the last test can be read in the[> Diagnosis/maintenance > Tests > Full
stroke test (FST)] folder.
Note
In total, seven stroke tests (PST plus FST) with
report and diagram can be displayed.
Test completed successfully
The following analysis parameters are shown
after a completed full stroke test (FST).
− Time stamp− Dead time (rising): time until the firstmeasurable movement of the valve fromthe closed position is detected.
− Dead time (falling): time until the firstmeasurable movement of the valve fromthe maximum open position is detected.

EB 8389-2 EN

47

Tests− T86 (rising): time which the valve requires to move from the closed position
until it reaches 86 % of the final value inthe maximum open position.
− T86 (falling): time which the valve requires to move from the maximum open
position until it reaches 86 % of the final
value in the closed position.
− T98 (rising): time which the valve requires to move from the closed position
until it reaches 98 % of the final value inthe maximum open position.
− T98 (falling): time which the valve requires to move from the maximum open
position until it reaches 98 % of the final
value in the closed position.
− Test status− Breakaway pressure: pressure required
to move the valve from the idle position
when the test starts
Two test reports can be shown at one time
for comparison. The comparison test can beselected as required.
TROVIS 3793 > Diagnosis/maintenance > Tests> Full stroke test (FST) > Reports and diagrams− Time stamp (not write-enabled)− Dead time (rising) (not write-enabled)− Dead time (falling) (not write-enabled)− T86 (rising) (not write-enabled)− T86 (falling) (not write-enabled)− T98 (rising) (not write-enabled)− T98 (falling) (not write-enabled)− Test status (not write-enabled)

The results of the first full stroke test (FST)
performed with the current configuration areused as a reference test and are write-pro-48

tected. All other full stroke tests can be
write-protected manually:Î Checkbox.

Test not completed
If the test is canceled and no events have occurred that activate the fail-safe position, thepositioner changes to the 'Target operating
mode'.
The fail-safe position is activated when theforced venting is triggered and when the current is lower than 3.8 mA.
A test cancellation causes the 'FST: cancellation criteria met' status message to be generated with the assigned status classification.
If the test cannot be started, the 'FST: start
criteria not met' status message with the assigned status classification is generated.
Note
No graph is plotted when a test cannot be
started.
TROVIS 3793 > Diagnosis/maintenance >Configuration > Status classification− FST: cancellation criteria met:
, [ ], , ,− FST: start criteria not met:[ ], , , ,TROVIS 3793 > Diagnosis/maintenance >Device state > Status messages− FST: cancellation criteria met− FST: start criteria not met

EB 8389-2 ENTestsStart criterion

Test canceled

Table 7: Recommended action when thestatus message is generated
Test result

We recommend:

Current

Î Check input signal

Internal errorÎ Restart test

Timeout

Î Check seat and plugfor deposits or foreign
particles

No movement
possible
Start criteria

Î Check test configuration

Function
activeÎ Wait for the active test
to finish and restart
test.

Incorrect
operatingmodeÎ Set operating mode
corresponding to Table 6 and restart test.

Statistical analysis
Every time a full stroke test is started, one of
the following counters counts this event depending on the test status.
TROVIS 3793 > Diagnosis/maintenance > Tests> Full stroke test (FST)− Number of successful tests (not write-enabled)− Number of canceled tests (not write-enabled)− Number of failed start criteria (not writeenabled)

7.2.4

Reset

See Table 8

EB 8389-2 EN

49

TestsFig. 17: > Diagnosis/maintenance > Tests > Full stroke test (FST) > Reports and diagrams

Initialization'Reset diagnosis''Clear reports''Reset (standard)''Reset (advanced)'

Table 8: Resetting the full stroke test

Reset configuration

NO

NO

NO

YES

YES

Reset reports

NO

YES

YES

YES

YES

Reset histograms

NO

YES

YES

YES

YES

Reset reference test

NO

YES

NO

YES

YES

Reset status messages

NO

YES

NO

YES

YES

50

EB 8389-2 ENTests

7.3 Dead band
The difference in set point w that causes aminimal change in the valve position x is
termed ‘dead band’.
The valve dead band is affected by the friction hysteresis and the elastic processes inthe valve stem packing.
The test is started in the manual mode.
During the dead band test, the positioner
moves the valve in small steps through therange of 'Start set point' ±½ 'Span'. Afterevery step the positioner records the response of the valve position x.

The test starts at the 'Start set point' andends at position 1.
− 'Start set point' – ½ 'Span' in 'Start direction' = 'Minus' or− 'Start set point' + ½ 'Span' in 'Start direction' = 'Plus'
After the 'Delay time after set point change'elapses, the valve moves from position 1 toposition 2:− 'Start set point' + ½ 'Span' in 'Start direction' = 'Minus' or− 'Start set point' – ½ 'Span' in 'Start direction' = 'Plus'
After the 'Delay time after set point change'elapses, the positioner defines a further set
point change, which starts in position 2 andends at the 'Start set point'.

Fig. 18: > Diagnosis/maintenance > Tests > Dead band > Plotted over time

EB 8389-2 EN

51

TestsAnalysis and monitoring

The 'Test status' generates an 'Active'
message.
'Function check'is activated as thecondensed state.

The dead band test provides statements on
the minimum, maximum and average deadband:
− 'Min. dead band': minimum change inthe set point that causes a minimalchange in the valve position.
− 'Max. dead band': maximum change inthe set point that causes a minimalchange in the valve position.
− 'Average dead band': average change
in the set point that causes a minimalchange in the valve position.
A plotted diagram is generated after the test
is successfully completed. Two different typesof diagrams are available:− Plotting of the valve position [%] after filter [%] over set point [s]− Plotting of the valve position [%] and theset point after filter [%] over time [s]TROVIS 3793
1. − Target operating mode: MAN
TROVIS 3793 > Diagnosis/maintenance >Tests > Dead band > Configuration
2. − Start set point: 0.0 to 100.0 %, [50.0 %]− Start direction: Minus, [Plus]− Span: 1 to 50 %, [1 %]− Delay time after set point change:
0.2 to 25.0 s, [1.0 s]
3. ! Start dead band test

Note
Cancel the test by right-clicking 'Stop test'
and selecting 'Execute' or by pressing the rotary pushbutton on the positioner. After thetest has been canceled, the positioner remains in manual mode.

Defining parameters

Reset initialization

See Table 9'Reset (advanced)'

Table 9: Resetting the dead band test

Reset

'Reset (standard)'

3. Start test.

7.3.1'Reset dead banddata'

2. Select test parameters.

'Reset diagnosis'

1. Switch to MAN mode.

Reset configuration

NO

NO

YES

YES

NO

Reset reports

YES

YES

YES

YES

NO

Reset measured data and diagram

YES

YES

YES

YES

NO

52

EB 8389-2 ENTests

7.4 Valve signature (Tests)
To assess the valve, the valve signature canbe recorded again in a repetition test andcompared with an already recorded reference (see section 6.4).
The repetition test is performed in the same
way as the plotting of the reference graphdescribed in section 6.4.1: the valve is
moved from the unpressurized end position
until it is close to the maximum open position
and back again. To perform this function, thepneumatic modules switch to open-loop control (control without feedback).
After the valve signature has been plotted,
the recorded values for 'Pressure (supply)','Pressure (exhaust)' and the valve position
are converted into fixed points.
Defining parameters
1. Switch to MAN mode.

Note
Cancel the test by right-clicking 'Stop test'
and selecting 'Execute' or by pressing the rotary pushbutton on the positioner. After thetest has been canceled, the positioner remains in manual mode.
Analysis and monitoring
A plotted diagram is generated in the [ >Diagnosis/maintenance > Tests > Valvesignature > Reports and diagrams] after thetest is successfully completed.
The test report of the reference (initialization)and the report of the last repetition test (Test)
are shown at the same time for comparison
purposes.
Reset
See Table 10

2. Start test.
The 'Test status' generates an 'Active'
message.
'Function check'is activated as thecondensed state.
TROVIS 3793
1. − Target operating mode: MAN
TROVIS 3793 > Diagnosis/maintenance >Tests > Valve signature
2. ! Start repetition test

EB 8389-2 EN

53

Reset initialization'Reset (advanced)''Reset (standard)'

Table 10: Resetting the valve signature(test)'Reset diagnosis'

Tests

Reset configuration

NO

YES

YES

NO

Reset reports

YES

YES

YES

NO

Reset measured data and diagram

YES

YES

YES

NO

Fig. 19: > Diagnosis/maintenance > Tests > Valve signature

54

EB 8389-2 ENError messages and recommended corrective action

8 Error messages and recommended corrective action
Message

Recommended action

Status classification> Diagnosis/maintenance > Device state > Status messages … Control valve diagnosis
Friction change (open pos.)See section 6.3.

YES [

]

Friction change (mid-pos.)See section 6.3.

YES [

]

Friction change (closed pos.)See section 6.3.

YES [

]

Valve sign. failed

Î Check configuration.
Î Restart valve signature.
Î Initialize positioner with setting 'Init.
with valve signature' = Yes.

YES [

]

No supply press.

Î Check air supply.
Î Check air lines/connections.

YES [

]

Low supply pressureÎ Check air supply.
Î Check supply pressure regulator.
Î Check air lines/connections.

YES [

]

Supply pressure > 10 bar

Î Check air supply.
Î Check supply pressure regulator.

YES [

]

PST: cancellation criteria met

See section 7.1.

YES [

]

PST: start criteria not met

See section 7.1.

YES [

]

FST: cancellation criteria met

See section 7.2.

YES [

]

FST: start criteria not met

See section 7.2.

YES [

]

P3799: failureÎ Check air quality.
Î Contact SAMSON's After-sales
Service.

YES [highest classification]

P3799: movement impairedÎ Check air supply.
Î Contact SAMSON's After-sales
Service.

YES [highest classification]

P3799: maintenance requiredÎ Check air supply.

YES [highest classification]

P3799: initialization error

Î Contact SAMSON's After-sales
Service.

YES [highest classification]

AMR signal outside range

Î Check attachment.

YES [Hardware error

Î Confirm error and select AUTO
operating mode.
Î Re-initialize positioner.

YES [highest classification]

EB 8389-2 EN]

55

Error messages and recommended corrective action

Message

Recommended action

Status classification

Limit for total valve travel exceededÎ Check valve and attachment forsigns of wear.

YES [

]

Lower end position shiftedÎ Check plug and seat for wear (seesection 6.2).

YES [

]

Upper end position shiftedÎ Check plug and seat for wear (seesection 6.2).

YES [

]

Dynamic stress factor exceededÎ Check the state of the valve packing(see section 6.1.4).

YES [

]

Set point deviation

Î Check attachment.
Î Check air supply.
Î Check air lines/connections.

YES [

]

BrownoutÎ Check power supply/input signal.

YES [

]

Current too low

Î Check power supply/input signal.

YES [

]

IP shutdown

Î Check power supply/input signal.

YES [

]

Current too highÎ Check power supply/input signal.

YES [

]

Angle limitation

Î Check attachment.

YES [highest classification]

Temperature inside device below min. limit

Î Check the installation of the control
valve concerning possible
environmental and ambient
influences. If necessary, protect thecontrol valve better against
environmental influences.

YES [

]

Temperature inside device
above max. limit

Î Check the installation of the control
valve concerning possible
environmental and ambient
influences. If necessary, protect thecontrol valve better against
environmental influences.

YES [

]

Logging suspended

The positioner's functioning is not
impaired. The message no longer
appears after the positioner starts
logging again.

YES [

]

Operating range in CLOSED
positionÎ Check attachment.
Î Check supply pressure.
Î Check whether another valve canbe used.

YES [

]

56

EB 8389-2 EN

Message

Recommended action

Status classification

Operating range in max.
OPEN position

Î Check attachment.
Î Check supply pressure.
Î Check whether another valve canbe used.

YES []Operating range shifting towards CLOSED position

Î Rethink the working range.

YES [

]

Operating range shifting towards max. OPEN position

Î Rethink the working range.

YES [

]

Limited working range: lower
range

Î Check that pneumatic installations
and connections are tight.
Î Check supply pressure.
Î Check plug stem for external
influences that could be blocking it.

YES [

]

Limited working range: upperrangeÎ Check that pneumatic installations
and connections are tight.
Î Check supply pressure.
Î Check plug stem for external
influences that could be blocking it.

YES [

]

Leakage: level limit 1 exceededÎ Check plug and seat for wear.

YES [

]

Leakage: level limit 2 exceededÎ Check plug and seat for wear.

YES [

]

Fail-in-place module

Fail-in-place module has been
YES [activated. No action possible. The
error message is cleared as soon as theconditions that caused the status
messages to be generated no longer
prevail.

]If the error message does not clear:Î Contact SAMSON's After-sales
Service.

EB 8389-2 EN

57

58

EB 8389-2 EN

EB 8389-2 EN

59

SAMSON AKTIENGESELLSCHAFT
Weismüllerstraße 3 · 60314 Frankfurt am Main, Germany
Phone: +49 69 4009-0 · Fax: +49 69 4009-1507
samson@samsongroup.com · www.samsongroup.com

2023-08-11 · English

EB 8389-2 EN