Siemens SIMATIC S5 Manual page 209

IP 265 Expansion
Programming the CPU
Because this sample application includes bilateral data transfers between IP 265 and CPU and a
connection via the expansion interface, the CPU user program must be written to include the
following:
• The control word for both IP 265s (including matching of their operational states)
• Evaluation of the status word for both IP 265s and
• Entry and deletion of parameters
• Structure of the CPU program section for control of two expanded IP 265s:
This section of the CPU program comprises three nesting levels. The function blocks invoked
by OB1 are processed cyclically.
OB1
JU FB 1
BE
Level 1
* FB1 "CONTROL": Read and evaluate status word, write control word, invoke FB2 "IP-PARAM"
FB2 "IP-PARAM": Read and process output parameter, generate input parameters
Figure 10-5. Structure of the CPU Program Section for
If the two IPs are in slots 2 and 3, the CPU program section for controlling the IP 265s might be as
follows:
12-10
FB1
*
Name: CONTROL
JC FB 2
BE
Level 2
Controlling two Expanded IP 265s
FB2
*
Name: IP-PARAM
BE
Level 3
EWA 4NEB 812 6130-02a
IP 265