Principle Of Job Order Processing - Siemens SIMATIC S5 Manual

IP 266
1.4 Operator Servicing Options (PLC and PG) and Their Priorities
The IP 266 can be controlled via a programmer (PG) or via the programmable con-
troller's CPU.
If job requests are issued to the IP 266 over both interfaces in the same firmware
cycle, the request issued via the programmer has priority but the next PLC job
request is serviced in the subsequent cycle. If this request differs from the PG
request and the latter is still being serviced, the IP 266 aborts the job and flags an
error.
PLC
Status info
PLC
interface
Figure 1-4. Principle of Job Order Processing
The IP 266 accepts two types of positioning requests:
• Single job orders (or requests) are forwarded to the IP 266 over the program-
mer port or the PLC interface.
Single job orders are all modes with the exception of mode 8 (AUTO) and
mode 9 (AUTO single block).
• Machining programs, i. e. a continuous sequence of single job orders, dwells,
corrections and switching operations.
The machining programs must be in the IP 266's memory. A machining pro-
gram is started over an operator interface by specifying the operating mode
and the program number.
EWA 4NEB 812 6057-02
IP266
positioning module
Job order
processing
System Overview
PG
Status info
Programmer
interface
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