Technical data

➣
The PLC control program changes the output byte to be transmitted
(PY 7).
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At the point when the HDB is executed, the CP 5430 TF/CP 5431 FMS
rechecks all the (GP) output bytes for changes (new/old comparison)
and only transmits the GP bytes which have changed since the last
"new/old" comparison.
Result
: the CP 5430 TF/CP 5431 FMS only transmits a GP byte in the
cycle-synchronized mode, when its value has changed between two
consecutive new/old comparisons.
The value of the GP byte at the time of the new/old comparison which you
decide in the control program (by means of an HDB send call with job
number 210) is decisive. If a byte changes its value several times but has
returned to its original value at the time of the "new/old" comparison, these
changes are not detected.
Communication with Global I/Os B8976060/01
Volume 1 9 - 12