Samson 3785 series, Mounting And Operating Instructions

Page: 55 / 80

If the status of the transmitted set point is "bad" (value < 64) or the positioner has not
been successfully initialized, it remains in fail-safe position (out of service).
The action determined by the parameter FSAFE_TYPE (fail-safe action) is caused by
the following events:
Start-up of the positioner (warmstart).
Elapsing of the DP-watchdog through interruption of the cyclic communication
with a Master Class 1 (not applicable, when communication is terminated
properly).
Elapsing of FSAFE_TIME in Automatic or Remote Cascade operating mode,
when the status of the reference variable, SP or RCAS_IN, valid in this operating
mode is set to "initiate fail-safe".
Receipt of a DP- "Global Control" service, for which the CLEAR bit is set
(not yet applicable for version K 1.30).
By setting the status of the reference variable used in the valid operating mode to
"bad", the actuator always moves to the fail-safe position determined by the spring
action (for version K 1.30 and higher).
Positioner manufacturer
DEVICE_MAN_ID
Clearly identifies the manufacturer of the field device.
Read-only.
Product number positioner
DEVICE_PRODUCT_NUM (M )
Manufacturer’s product number of the positioner.
Proportional-action coefficient
KP_Y1
SERVO_GAIN
Proportional-action coefficient
KP_Y2
Default:
Proportional-action coefficient for supply air.
In writing, the value is written to KP_1 (supply air) and KP_Y2 (exhaust air).
Proportional-action coefficient exhaust air.
In writing, the value is written to KP_Y2 (exhaust air). KP_Y1 (supply air) remains
unchanged.
We recommend to adjust the value in increments of 0.1 when adjusting the value in the
range from 0.01 to 10.0. If the value is increased, the set point will be attained faster.
Range: 0.01 to 10.0
1.2
Note:
When the positioner is initialized for the first time, the proportional-action coefficients
KP_Y1 and KP_Y2 are determined.
The initialization values listed in the table on the following page might have to be
adapted to the modified operating conditions in order to achieve optimum control
behavior.
EB 8382-1 EN
55
List of parameters