Technical data

Possibilities of error detection
➣
Group error message in ANZW (RECEIVE ANR 210)
➣
Reading the station list (ANR 201).
Error statuses within the bus system including GP processing are written to
the station list. Using a cyclic CONTROL call and a RECEIVE handling
block call, the user program can read out the station list. In the status byte
for GP processing (ANR = 210) an error which occurs in the GP processing
is indicated as a "group error message" so that the station list must only be
read out in case of an error. If the cycle-synchronized processing mode is
set, "cycle overflow" is also entered in the station list. A cycle overflow can
occur when changes in the GP output bytes cannot be transmitted owing to
a lack of bus capacity (PLC cycle is faster than the bus token cycle). The
failure of a GP transmitter is also indicated in the station list. The station list
can be read out with ANR 201 using the RECEIVE block.
B8976060/02 Communication with Global I/Os
9 - 17 Volume 1