Siemens SIPART PS2 Service Manual page 68

Appendix A
A.4 SIPART PS2 Valve Positioner Fail-Safe Positions
FSAC, Fail Safe factory: As per power failure modes indicated in above table:
● Single-acting models - Y1 exhaust to zero pressure.
● Double-acting models- Y2 exhaust to zero and Y1 increases to supply pressure.
FSTI, Fail Safe Time: Elapsed time after communication loss before going to safety position.
FSVL, Fail Safe Valve: Safety position upon communication loss, pre-requisite: FSTY=FSVL
Foundation Fieldbus Parameters
The following Analog Output Block safety parameters are accessible only via Foundation
Fieldbus configuration software, i. e.: National Configurator.
IO_OPTS:
Faultstate Type (bit 6) = 0 or unchecked will hold last position upon loss of communication.
Faultstate Type (bit 6) = 1 or checked will position actuator as per "FSTATE_VAL"
parameter.
FSTATE_VAL:
Desired actuator position upon loss of digital communication, Faultstate Type must = 1.
FSTATE_TIME:
Elapsed time after communication loss before going to safety position.
Safety Shutdown
Profibus only positioners are equipped with an additional input to drive an actuator to the
PS2's factory safety position; see Figure A-3 Reaction to failure of auxiliary powers above.
See Figure A-4 Reaction to failure of auxiliary power with fail in place above if unit has Fail-
in-Place option.
To activate this feature, change position of 'Shut Down' jumper located underneath
secondary cover.
Once enabled, 24Vdc must be maintain on terminals 81 and 82. Otherwise, the positioner
will drive the actuator as shown in Figure A-3 Reaction to failure of auxiliary powers above.
See Figure A-4 Reaction to failure of auxiliary power with fail in place above if unit has Fail-
in-Place option.
● Single-acting models - Y1 exhausts to zero pressure.
● Double-acting models- Y2 exhausts to zero and Y1 increases to supply pressure.
Once enabled, this feature will override any soft parameter settings as mentioned above.
66
PS2 Troubleshooting Guide
Service Manual, 03/2017, A5E36661550-AA