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MOV_INCH – Logic Block Documentation

Overview

The MOV_INCH block is designed to control Motor Operated Valves (MOVs) with inching functionality. It is widely used in industrial automation to allow precise, step-wise operation of valves, providing both automatic and manual (HMI-based) control. This document details the logic behavior, input/output signals, and operational parameters of the MOV_INCH logic block.

  • The block ensures that all operational constraints such as interlocks, permissions, feedback, and timeouts are satisfied before commanding valve operations.

Logic Block Illustration

  • A visual representation of the MOV_INCH block showing its place in the logic and I/O system.
  • Example diagrams include input/output wiring and HMI control integration.

../../Images/Programing_Manual/Logic_Manual/MOV_INCH/Bl_mov-inch.png

In above picture, we are showing inputs and output of MOV_Inching block.

../../Images/Programing_Manual/Logic_Manual/MOV_INCH/Signal_mov-inch.png

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.
ioTSO BIT Torque Open Feedback – Torque switch signal when valve opens.
ioTSC BIT Torque Close Feedback – Torque switch signal when valve closes.
ioZSC BIT Valve Close Feedback – Indicates valve is fully closed.
ioRunFB BIT Feedback indicating the motor is running.
ioTripFB BIT Indicates motor tripped (e.g., via protection relay).
HMI_OPEN_INCH BIT Momentary command from HMI to inch the valve open.
HMI_CLOSE_INCH BIT Momentary command from HMI to inch the valve close.
AUTO_OPEN_INCH BIT Momentary open inch command from other logic (Auto mode).
AUTO_CLOSE_INCH BIT Momentary close inch command from other logic (Auto mode).
Mode BIT Manual = 0, Auto = 1.
ioOPEN_CMD BIT Output signal to open the valve (momentary pulse).
ioCLS_CMD BIT Output signal to close the valve (momentary pulse).
perm_Open BIT External permissive for open command. Must be TRUE to allow operation.
perm_CLS BIT External permissive for close command.
intl BIT Interlock. TRUE means interlock is active and motion is blocked.
FB_Fault BIT ZSO/ZSC not received within the configured window.
CMD_Fault BIT Run feedback not received after command or received unexpectedly.
unrecog_operation BIT Valve is running but feedback is missing or inconsistent.
Run_FB_Timer REAL Time allowed for RunFB to respond after command is issued.
Run_FB_Counter REAL Runtime counter while waiting for motor run feedback.
ZS_Timer BIT Active while valve is moving (ZSO → ZSC or vice versa).
ZS_Counter REAL Time duration of current valve movement.
opened_time REAL Total accumulated open time.
closed_time REAL Total accumulated close time.
open_count DINT Number of open inching operations.
close_count DINT Number of close inching operations.
R_Trig_ZSO R_TRIG Rising edge trigger for Open feedback signal.
R_Trig_ZSC R_TRIG Rising edge trigger for Close feedback signal.
valve_running BIT TRUE when the valve is in motion.
HMI_Interface_hardware WORD Interface data exchanged with HMI.
CycleTime REAL Execution cycle time of the logic block.
Desc STRING(10) Short description or tag (max. 10 characters).
TagName STRING(12) Valve identifier (max. 12 characters).

Operational Summary

  • The MOV_INCH block allows inching (momentary jog) control in Manual (HMI) or Auto (logic) mode.
  • Inching commands must be momentary pulses; each pulse causes a small valve movement.
  • Only one command (open or close) is active at any time.
  • Before executing commands, permissives and interlocks are validated.
  • Feedback signals (ioZSO, ioZSC, ioRunFB) confirm valve position and motion.
  • Fault detection logic ensures command execution is verified by feedback within time limits.
  • Timers and counters track runtime, usage analytics, and valve behavior.
  • Intended for valves requiring precise, short-step motion with high control granularity.

Training Demo Video

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

MOV-INCH Block Demo - TPW Logic Setup

Best Practices

  • Always validate PERM_OPEN, PERM_CLOSE, and INTERLOCK before motion.
  • Use rising edge detection (ZSO_TRIG, ZSC_TRIG) to count operations accurately.
  • Set inching command pulse duration and timeout (INCH_TIMEOUT) based on actuator specs.
  • Use conservative values for feedback timeouts to prevent false positives.
  • Manually reset faults and trips after resolving physical or electrical issues.

End of MOV_INCH Logic Block Documentation