Siemens SIMATIC ET 200S - Page 97

Configuration Options
3-33
ET 200S Distributed I/O System
EWA-4NEB 780602402-12
4. Create a user program:
-- Create OB 61.
-- At the beginning of OB 61, SFC 126 must be called to upgrade the partial
process image of the inputs.
-- At the end of OB 61, SFC 127 must be called to upgrade the partial process
image of the outputs.
-- The partial process image to be used is the one parameterized in the CPU
(”Clocked Interrupts” tab).
Troubleshooting in clocking
Action Cause Correction
Station failure of the
ET 200S
Errored clocking (more than
10 lost or interrupted
cycles).
Check the parameter
assignment.
The equidistance times are
too long.
The input delays of the
HIGH FEATURE digital input
modules are not optimally
set.
Decrease the input delay of
the HIGH FEATURE digital
input modules.
No clocked
signal detection/output.
Wrong process image
partition used
Neg. RET_VAL in the case
of SFCs 126/127
Check whether the same
process image partition was
used in the OB 61 user
program (or up to OB 64)
when SFCs 126/127 are
called and in the
configuration of the DP
master/DP s lave.
Further information
You can find additional information on clocking in the STEP 7 help system and in
the Isochrone Mode manual.