Omron SYSMAC CJ - REFERENCE MANUAL 08-2008 Reference Manual page 458

Increment/Decrement Instructions
Flags
Precautions
Examples
418
The Equals Flag will be turned ON if the result is 0000 and the Carry Flag will
be turned ON when a digit changes from 9 to 0.
Both the Equals Flag and the Carry Flag will be turned ON when the content
of Wd changes from 9999 to 0000.
Name Label
Error Flag ER
Equals Flag =
Carry Flag CY
The content of Wd must be BCD. If it is not BCD, an error will occur and the
Error Flag will be turned ON.
Operation of ++B(594)
In the following example, the BCD content of D00100 will be incremented by 1
every cycle as long as CIO 000000 is ON.
Incremented every cycle
while CIO 000000 is ON.
Wd: D00100
Operation of @++B(594)
The up-differentiated variation is used in the following example, so the content
of D00100 will be incremented by 1 only when CIO 000000 has gone from
OFF to ON.
@++B
Wd: D00100
Wd
ON if the content of Wd is not BCD.
OFF in all other cases.
ON if the content of Wd is 0000 after execution.
OFF in all other cases.
ON if a digit in Wd went from 9 to 0 during execution.
OFF in all other cases.
Wd: D00100
: Execution of ++B(594)
Increment Increment Increment Increment
Incremented only for
up-differentiation.
Wd: D00100
: Execution of @++B(594)
Increment Increment
Section 3-10
Wd
Operation