Digital Input HW_DI-4
This bit reports the status of the contact connected to the actuator
hard-wired ESD terminals. The input can be used to control the
actuator or simply to report the status of a plant feedback signal. The
function is set in the Auxiliary Input Mask parameter, which
determines whether the bit is reported as true (1) for a closed contact
or an open contact and whether the input controls the actuator or not.
Note that the input is always reported even when it is also controlling
the actuator.
A configuration feature also allows HW_DI-4 to be set to act as a
‘Disable Fieldbus Control’ input. In this mode, when the input is
applied (irrespective of the Auxiliary Mask setting) the actuator cannot
be controlled over the network. This can be useful during plant
commissioning to prevent unwanted valve movement.
5.2.3 Discrete Inputs reporting the FF CP card condition
Watchdog Recovery
The FF CP card’s watchdog automatically resets the processor if it is
tripped. This bit will be true (1) following a watchdog trip for the time
period set in the associated watchdog timeout parameter.
Part Stroke Error In order to perform a partial stroke of the valve, the starting position is
specified as either the open limit or the close limit. If the actuator is
commanded to perform a partial stroke when it is not in the correct
starting position or when it is in a mid-position, this error is generated
and the bit will be set (1).
There is a timer associated with Partial Stroke that is set in the
Transducer block during set-up. It must be set to a value long enough
to cover a successful part stroke operation from end to mid-position
and back to the end. If the actuator fails to complete the partial stroke
within the time set, then this bit will be true (1).
Once set, the Part Stroke Error bit will be reset to 0 when the actuator
next moves at least 2% by either a manual or automatic operation.
Partial Stroke in Progress
When the actuator is performing a partial stroke this bit is true (1).
Once the action is complete the bit is reset (0). If the partial stroke is
interrupted by a new command then the bit will be reset.
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