Pulse Output 1 PV Overflow/Underflow

What does A281.01 mean?

This flag indicates that the Pulse Value (PV) for pulse output 1 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 1 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.

• Pulse Output 1 PV incremented beyond 7FFF FFFF hex (2,147,483,647), causing an overflow.
• Pulse Output 1 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 1 exceeding the PV's capacity.
• Unexpected external inputs or noise causing rapid or sustained pulse counting in one direction for output 1 without appropriate PV reset.

Click steps to track your progress.

1. 1

   Review the application ladder program logic that controls pulse output 1 to identify conditions leading to PV exceeding the 32-bit range.

2. 2

   Verify the target pulse count specified in instructions like PULS(886), PLS2(887), or IFEED(892) for output 1 is within the acceptable PV range.

3. 3

   Execute the INI(880) instruction for pulse output 1 to reset its PV.

4. 4

   Toggle the Pulse Output 1 Reset Bit A541.00 from OFF to ON to clear the PV for pulse output 1 (documented on page 183).