Controls Priority - rotork Modbus IQ Pro Technical Manual

Modbus MFU Option Card Installation Manual
5.1.1

Controls Priority

Since there are three potential sources for control inputs the actuator and Modbus Module assign a
priority for those occasions when two or more commands are applied simultaneously.
In addition, for the IQ / IQT and SI / EH actuators, the remote control hard wired inputs can be used as
discrete input signals, to report the status of other devices or as control inputs. The associated
Auxiliary Input Mask parameter must be set for the IQ / IQT or SI / EH to select the required function.
In the case of the hard wired input for ESD this can be configured either as an ESD/DI-4 signal or as a
'Modbus Command Inhibit' to prevent network control signals from moving the actuator.
 Low Priority
High Priority
Local Stop
Hard Wired ESD
Modbus ESD
 Mechanically interlocked to prevent both at the same time.

The IQ/IQT and SI/EH can be set so that Local Stop has a higher priority than ESD.

Only one Modbus command is possible at a time.

If a Modbus command is applied whilst Hard Wired Stop is present, stop is cancelled.
Fig 22:
In the case of the Q actuator the control selection is slightly different because the actuator uses a
different control circuit. The Local Controls have a higher priority than hard wired or Modbus controls
and the hard wired and Modbus controls share the same priority level

If the Stop/Maintain hard wired input is closed (to provide maintained action on the other
contact inputs to the actuator) then position control via Modbus cannot be used.

The recommended connection is to use only an open and close buttons or contacts and
'push to run' mode where the actuator only moves whilst the contact is closed.

If a Modbus and hard wired input are both present the control priority is set by the actuator
priority setting
 Low Priority
High Priority
Local Stop
Hard Wired ESD
Modbus ESD

Mechanically interlocked to prevent both at the same time.
 The action depends on the Actuator Control Priority setting.
 Only one Modbus command is possible at a time.

A Modbus Position command must not be applied whilst Hard Wired Maintain is present.

A Modbus Stop command is not possible if Hard Wired Maintain is present.
Fig 23: Q Controls Priorities
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Local Close Hard Wired Close
Local Open Hard Wired Open
Hard Wired Stop
IQ / IQT and SI / EH Controls Priorities
Local Close
Local Open
Publication PUB091-003-00_0119


Hard Wired Close
Hard Wired Open
Modbus Close
Modbus Open
Modbus Close
Modbus Open
Modbus Stop
Modbus Position
Hard Wired Stop/Maintain
Modbus Position
Modbus Stop