Siemens SIMATIC S7-300 FM 350-1 - Operating the Interface with Full Acknowledgement Principle

Programming the FM 350-1
5.7 Programming FM 350-1 without FCs
FM 350-1 Counter module
68 Manual, 05/2011, A5E03648639-01
5.7.5 Operating the interface with full acknowledgement principle
Complete Acknowledgement Principle
The complete acknowledgement principle is always used to control the FM 350-1 from the
user program:




W
W
&RQWUROELW
&KHFNEDFNELW
Figure 5-4 Complete Acknowledgement Principle
The sequence is as follows:
1. If the feedback bit = 0, you can request processing via the user program by setting the
control bit.
2. The FM 350-1 detects the request, acknowledges it by setting the feedback bit and starts
the processing.
3. Once the FM 350-1 has set the feedback bit, you can reset the control bit.
4. At the end of processing, the FM 350-1 responds to the resetting of the control bit by
resetting the feedback bit.