Siemens SIMATIC S5 Manual page 224

IP 265
Programming the CPU
Because the CPU and the IP 265 interchange parameters in this example, the CPU user program
must be written to include not only the control word (IP 265 RUN, IP 265 STOP) and the status word
(operational status, error diagnostics), but also reading of the output parameters.
• Structure of the CPU program section for controlling the IP 265
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, call FB2 "IP-PARAM"
FB2 "IP-PARAM": Read and process output parameters
If the IP 265 is in slot 2, the section of the CPU user program for controlling the IP 265 might look
as follows:
• Entries in the SIMATIC assignment list:
Operand Symbol
IW 82
I 84.0
EWA 4NEB 812 6130-02a
FB1
*
Name: CONTROL
JC FB 2
BE
Level 2
Figure 13-6. Structure of the CPU Program Section for
IP 265 Control with Parameter Interchange
Sample Applications and Programming Aids
FB2
*
Name: IP-PARAM
BE
Level 3
Comments
Count for correction
Scan: Counting terminated
13-11