Siemens SIMATIC CP 340 User Manual page 108

Communication using function blocks
6.3 Using the function blocks for connecting to a communications processor
Time Sequence Chart for P_SEND (FB 3)
The figure below illustrates the behavior of the DONE and ERROR parameters, depending
on how the REQ and R inputs are wired.
Figure 6-1
Note
The REQ input is edge-triggered. A positive edge at the REQ input is sufficient. The result of
the logic operation must not be at "1" at any point during transfer.
108
Time Sequence Chart for P_SEND (FB 3)
PtP coupling and configuration of CP 340
Manual, 04/2011, A5E00369892-03