Samson 3785 series, Mounting And Operating Instructions

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Control loop error
This message is displayed when the positioner fails to control the adjusted range of tolerance
for error messages within the preset delay time.
Possible sources of error:
– Oscillation caused by actuator operated too fast (small travel volume)
Remedy: Reduce supply air pressure as per chapter 3.1.2 or install a signal pressure throttle.
– Supply air failure/supply air insufficient
– Filter clogged
– Solenoid valves oiled-up
– Actuator diaphragm ruptured
– Actuator springs broken
– Considerable increase of friction at the control valve
– Control valve blocked
The messages are indicated by bit 7 and bit 13 of the CHECKBACK parameter (refer to
table on pages 38/39). Bit 7 is automatically reset, whereas bit 13 is reset by means of the
"SELF_CALIB_CMD = 10" command (reset ’control loop fault’).
Positioner inactive (MODE = out of service)
This message is generated if the positioner is in the "OUT OF SERVICE" mode.
Device in selftest mode (MODE = out of service)
This message is generated if the device is in the initialization phase or adjusting electrical
zero.
Limit value of total valve travel exceeded
The current value of the total valve travel lies above the limit value entered or preset.
If this limit value is preset slightly below the value determined for a reference valve, the posi-
tioner automatically signals that the valve needs to be maintained so that possible failure is
prevented. Reset via "SELF_CALIB_CMD = 7" command (reset total valve travel)
64
EB 8382-1 EN
Messages and diagnosis