5/12/2017
TECH-538/D.W.O. 23160
Page 116 of 189
In the AO configuration, check the following parameters:
o
IO_OPTS
: if IO_OPTS is ‘0’, the value will hold the current value (freeze) if a fault is detected.
If IO_OPTS is ‘1’, the output will go to the preset FSTATE_VAL value, if a fault is detected.
o
STATUS_OPTS
: options of status which the user may select in the block processing.
o
FSTATE _TIME
: the time, in seconds from detection of failure of the output block remote
setpoint to the output action of the block output if the condition still exists.
o
FSTATE_VAL
: the preset SP value to use when failure occurs. This value will be used if IO_OPTS =
“Fault State to value” is selected.
The valve does not STOP at last position when communication is lost
Fail last applications depend on additional pneumatic assembly to keep the air trapped in the actuator in the event
of a failure.
ICoT is not communicating with the FF Host
When there is regular FF communication, the ICoT has an address in the range 0x10 to 0xF7 and it should be
present in the Host live list, (sometimes presented commissioned or uncommission device list, etc.). If the ICoT
does not detect any valid activity in the bus then the display will show the message “NO RUN FF Comm. Error”.
In this case check wiring, connectors, terminators, bus voltage (between 9V and 32V), barriers, and signal quality.
Indication of valve closed or valve opened is wrong
Check the parameters “Signal Action” and “FLOP”. Change the configuration of these parameters according the
application’s requirements. (See Section 11.4.3)
Valve is not moving according to the AO block setpoint
•
Check pneumatic connections, air supply pressure, solenoid valve wiring.
•
Check AO BLOCK_ERR parameter for configuration errors and make sure all mandatory parameters
are properly configured: MODE_BLK, CHANNEL, SHED_OPT, PV_SCALE and XD_SCALE.
(See Section 11.4.3)
•
Check if the associated Transducer block actual mode is AUTO.
AO block mode is IMAN or AUTO
•
The AO Cascade input has a status attribute of BAD. Check if the configuration was downloaded
without errors. Check if the publisher block is working as expected. Check the configuration of the
link between the publisher block and the AO.
•
Status attribute of READBACK parameter is BAD. Check the transducer configuration.
Check the positioner regarding calibration and installation.
•
Status attribute of back-calculation parameter is Good - Fault State active, local over-ride, not
invited, or initialization request. Check the Faults state options and any FSTATE condition that may
be active (See section 8.6). Check the publisher block’s output status and configuration.
