Pulse Output 2 PV Overflow/Underflow
Omron · SYSMAC CJ Series PLC
What does A326.01 mean?
This flag indicates that the Pulse Value (PV) for pulse output 2 has either exceeded its maximum positive limit (overflow: incremented beyond 7FFF FFFF hex) or fallen below its minimum negative limit (underflow: decremented below 8000 0000 hex). This signifies that the cumulative pulse count for output 2 has gone out of its defined 32-bit range, wrapping around to the opposite extreme, and can no longer accurately represent the total number of pulses.
Common Causes
- Pulse Output 2 PV incremented beyond 7FFF FFFF hex (2,147,483,647), causing an overflow.
- Pulse Output 2 PV decremented below 8000 0000 hex (-2,147,483,648), causing an underflow.
- An application program error or miscalculation resulted in a commanded pulse count for output 2 exceeding the PV's capacity.
- Unexpected external inputs or noise causing rapid or sustained pulse counting in one direction for output 2 without appropriate PV reset.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Review the application ladder program logic that controls pulse output 2 to identify conditions leading to PV exceeding the 32-bit range.
- 2
Verify the target pulse count specified in instructions like PULS(886), PLS2(887), or IFEED(892) for output 2 is within the acceptable PV range.
- 3
Execute the INI(880) instruction for pulse output 2 to reset its PV.
- 4
Toggle the Pulse Output 2 Reset Bit A542.00 from OFF to ON to clear the PV for pulse output 2 (documented on page 183).