Siemens SIMATIC S5 Manual page 291

IP 266
9.1.3 Programming the TOGGLE Bit
A change in the value of the TOGGLE bit informs the IP 266 that a new job
request is waiting to be serviced. The IP 266 then interprets and executes this
request .
Job n-1 Job n
To the IP 266 To the IP 266
with TOGGLE with TOGGLE
= "1" = "0"
Job request is Job request is
serviced serviced
In sample program 1, the TOGGLE bit is programmed in FB 25.
9.1.4 Error Analysis
Errors should be analyzed to enable the STEP 5 program to respond quickly to an
event.
It is recommended that errors be analyzed in every cycle. When doing so, how-
ever, you should also keep track of the "Job terminated" bit so that you will not
respond to "old" data.
EWA 4NEB 812 6057-02
Job n+1 Job n+2
To the IP 266 To the IP 266
with TOGGLE with TOGGLE
= "0" = "1"
Job request is Job request is
not serviced serviced
STEP 5 Programming
Job n+3 Job n+4
To the IP 266
with TOGGLE
= "1"
Job request is
not serviced
9-3