Siemens ET 200S Manual page 220

Interface Modules
Time Ti (Read in Process Values)
This value can only be set provided you have enabled the "Synchronize DP slave
with DP cycle" parameter.
Ti is the time reserved for reading in the input data at the ET 200S. At the
beginning of Ti, the input data is converted at the terminals and stored in a buffer
via the backplane bus of the ET 200S. Ti ends at the beginning of the next,
equidistant DP cycle (i.e. with the global control frame).
At this point, the most recent, most up-to-date input data must be available to be
read in on the PROFIBUS subnet. The time Ti must take into account the
processing and delay times in the modules and in the backplane bus of the
ET 200S and, in the case of modular slaves, is therefore dependent on the
configuration.
The time Ti can only be set in the specified increments between the minimum and
maximum values. Normally, the default values should be accepted.
Time To (Output Process Values)
This value can only be set provided you have enabled the "Synchronize DP slave
with DP cycle" parameter.
The end of the To time is the point at which the output data is switched to the
module terminals in its converted form. The time To includes the following:
S Distribution of the output data via the PROFIBUS-DP bus system to the slaves
(= cyclic data-exchange master slave)
S Distribution of the output data to the modules via the backplane bus of the slave
S Conversion and transfer of the output data to the output terminals of the module
To starts with the arrival of the global control frame. Like Ti, the time can be set in
the specified increments between the minimum and maximum values. Normally,
you should accept the default values.
8-6
Distributed I/O System ET 200S
EWA 4NEB 780 6024-02 07