Modbus MFU Option Card Installation Manual
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Publication PUB091-004-00_0918
Moving Inhibited
This bit will be true (1) when the Motion Inhibit Timer is active or
the Interrupter Timer is active, or both are active.
The Motion Inhibit Timer is used in position control to prevent the
actuator from exceeding its prescribed number of starts per hour, or to
reduce the effects of hunting during closed-loop control.
The Interrupter Timer can be used over part or the entire actuator
stroke to slow down the effective speed of valve travel.
When under network control, the control signal does not need to be
re-applied when this bit is true, as the control action will continue once
the time has elapsed.
Position Control Enabled
This bit will be true (1) when a Position command is
being actioned. This data can be used to indicate that positioning
mode has control of the actuator.
Watchdog Recovery
The MFU 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
(Register 18).
Battery Low
The status of the internal battery is monitored and should it fall below
a critical level this signal will become true (1). The battery is used to
power the circuits used to keep track of the valve position when the
actuator mains power is lost. This battery is used only when the
actuator has no power feed and the valve is actually moved.
Open Interlock
The input contact to the Open Interlock is monitored by the MFU.
Whenever the input contact is closed this bit will be true (1). If the
actuator is not using the interlock function, then this input can be used
as a digital status feedback for a plant signal not associated with the
actuator. If the interlock circuit is being used, then this bit will indicate
the existence of an interlocking input that can prevent the actuator
from opening.
Close Interlock
The input contact to the Close Interlock is monitored by the MFU.
Whenever the input contact is closed this bit will be true (1). If the
actuator is not using the interlock function, then this input can be used
as a digital status feedback for a plant signal not associated with the
actuator. If the interlock circuit is being used, then this bit will indicate
the existence of an interlocking input that can prevent the actuator
from closing.
Digital Input DI-1
This bit reports the status of the contact connected to the actuator
hard wired
Open
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.
