Relay Ladder; Function Block - Allen-Bradley Logix5000 Reference Manual

Arithmetic Status Flags:
Fault Conditions:
Condition
Prescan
Rung-condition-in is false
Rung-condition-in is true
Postscan
Condition
Prescan
Instruction first scan
Instruction first run
EnableIn is cleared
Postscan
Compute/Math Instructions (CPT, ADD, SUB, MUL, DIV, MOD, SQR, SQRT, NEG, ABS)
To detect a possible divide-by-zero, examine the minor fault bit (S:MINOR).
See Logix5000 Controllers Common Procedures Programming Manual,
publication 1756-PM001.
Arithmetic status flags are affected.
A minor fault occurs if
The divisor is zero
Execution:

Relay Ladder

Action
The rung-condition-out is set to false.
The rung-condition-out is set to false.
Destination = Source A – (TRN ( Source A / Source B) * Source B )
The rung-condition-out is set to true.
The rung-condition-out is set to false.

Function Block

Action
No action taken.
No action taken.
No action taken.
EnableOut is cleared.
No action taken.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Fault type
4
Chapter 6
Fault code
4
281