MOV (Open/Close) Logic Block Documentation

Overview

The Motorized Operating Valve (MOV) is a vital component in industrial automation and fluid control systems. Designed for ON/OFF control, it facilitates automated flow regulation through electrically driven actuators, governed primarily by a Programmable Logic Controller (PLC).

• MOVs are extensively used in process industries—such as oil and gas, water treatment, chemical manufacturing, and power generation—where reliable and responsive flow control is essential.

• It supports both automatic and manual control modes, permission checks, interlock validation, command execution, and signal-based fault detection. The block outputs critical feedbacks to the HMI faceplates for operator, basic, advanced, and diagnostic views.

Logic Block Illustration

The MOV logic block provides a structured interface for automating and monitoring a motor-operated valve within a PLC-based control system. This block handles the execution of control commands, feedback processing, alarm generation, and interlock checks.

A visual representation of the MOV block showing its place in the logic and I/O system.

In the above picture, we are showing that how to use the MOV_Inching block.

Pins Information

Signal	Type	Description
ioZSO	BIT	Valve Open Feedback – Indicates valve is fully open.
ioZSC	BIT	Valve Close Feedback – Indicates valve is fully closed.
ioTSO	BIT	Torque Open Feedback – Torque switch signal when valve opens.
ioTSC	BIT	Torque Close Feedback – Torque switch signal when valve closes.
ioRunFB	BIT	Feedback indicating the motor is running.
ioTripFB	BIT	Indicates motor tripped (protection relay).
HMI_Open_CMD	BIT	Valve Open command from HMI.
HMI_CLS_CMD	BIT	Valve Close command from HMI.
Auto_Open_CMD	BIT	Valve Open command from other logic blocks (Auto mode).
Auto_CLS_CMD	BIT	Valve Close command from other logic blocks (Auto mode).
Mode	BIT	Manual = 0, Auto = 1.
ioOPEN_CMD	BIT	Output signal to open the valve.
ioCLS_CMD	BIT	Output signal to close the valve.
perm_Open	BIT	External permissive for Open command. Must be TRUE to allow motion.
perm_CLS	REAL	External permissive for Close command.
intl	BIT	External interlock. TRUE means interlock is active and motion is blocked.
FB_Fault	BIT	ZSO/ZSC not received within configured time.
CMD_Fault	BIT	Run feedback not received after command OR feedback received without command.
unrecog_operation	BIT	Valve is running without valid open/close feedback, e.g., inconsistent state.
Run_FB_Timer	REAL	Configured time to wait for motor run feedback after issuing command.
Run_FB_Counter	REAL	Runtime counter while waiting for motor run feedback.
ZS_Timer	BIT	Activates during valve travel from ZSO → ZSC or ZSC → ZSO.
ZS_Counter	REAL	Runtime duration of valve movement.
opened_time	REAL	Time duration the valve has been open.
closed_time	REAL	Time duration the valve has been closed.
open_count	DINT	Number of valve open operations (count).
close_count	DINT	Number of valve close operations (count).
R_Trig_ZSO	R_TRIG	Rising edge trigger for Open feedback.
R_Trig_ZSC	R_TRIG	Rising edge trigger for Close feedback.
valve_running	BIT	Internal signal indicating valve is in motion.
HMI_Interface_hardware	WORD	Hardware interface data exchanged with HMI.
CycleTime	REAL	Main program cycle time of logic block.
Desc	STRING(10)	Tag name of the MOV block (max. 10 chars).
TagName	STRING(12)	Description of the MOV block (max. 12 chars).

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Operational Summary

• The logic block operates in Manual (HMI control) or Auto (external logic) mode.
• Only one command is executed at a time (either open or close).
• Safety interlocks and permissives are evaluated before any valve motion.
• If feedback is missing or inconsistent, fault flags are raised.
• Motion duration and state transitions are monitored using ZS_Timers and Run Feedback Timers.
• Usage analytics (open/close count and duration) are tracked for diagnostics and maintenance.

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Training Demo Video

Demonstration video is available , How to use the Daca Logic Block through Library:

PID Block Demo - TPW Logic Setup

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Best Practices

• Always validate PERM_OPEN, PERM_CLOSE, and INTERLOCK before allowing valve movement.
• For safety, faulted valves (TRIP state) must be reset manually using the faceplate Reset button or RESET pin.
• Keep RUN_FB_TIMEOUT and ZS_FB_TIMEOUT parameters conservative to avoid false positives in slow-acting valves.

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Tip:
This logic ensures synchronized operation between field signals and faceplate visualizations, enabling safe and operator-friendly MOV control.