Technical data

Calculation of the reaction time T
R
of the global I/Os
In the CYCLE-SYNCHRONIZED mode, the time interval between HDB
SEND (RECEIVE) calls in the control program determines the reaction
times of the global I/Os.
In the FREE mode, you can calculate the minimum time interval between
two consecutive "changed value frames" (the CP sends only data whose
values have changed!).
This minimum interval, called the "reaction time" (T
R
) is a function of the
data rate and the selected target rotation time (TTR).
T
R
T
R
TTR
limit
TTR/
bit time units
1
2
1
2
Explanation of areas
and
:
1
If TTR is less than TTR
limit
, the CP sends changed
GP output bytes at the latest after a reaction time T
RMin
.
2
If TTR is greater than TTR , there is a linear relationship
according to the following equation (TTR in bit time units,
limit
T =---------------- *TTR
4
data rate
R
data rate in bps, T in seconds):
R
Min
Fig. 17.14 Reaction Times T
R
Appendix B8976060/02
Volume 1 17 - 32