Siemens S5-135U/155U - Manual (Page 167)

5-27
System Manual
C79000-G8576-C199-06
5.2.3 Interfaces of the CPU 948
This section contains information on the interfaces of the CPU 948.
You can use the PG interface on the CPU 948 either via the front connector
or via the 923C coordinator module and the S5 bus.
Note
Simultaneous operation of the PG interface via the front connector of the
CPU 948 and via the 923C coordinator is not possible. Switching the PG
online without a job request is already sufficient to operate the interface.
Electrically, it is merely a PG interface which can be operated via two
different terminals.
The connection to the PG can be established in every operational state of the
CPU.
You can also use the second interface of the CPU 948 as a PG interface.
Physical adaptation is achieved with a PG module (see also Section 5.9,
Interface Submodules).
A detailed description of PG interfaces can be found in the CPU 948
Programming Guide.
A PG-PLC link via SINEC H1 allows very advanced communication
between the partners. For example, the user software can be loaded into the
CPU 948 up to eight-times faster than with serial communication.
For this link you will need, in addition to the CPU 948, a CPU 143 (Version
w 2.1) in the PLC and a PG7xx with SINEC H1 connection and the STEP 5
single-tasking software from Version 6.0 or multi-tasking from Version 2.0.
Note
You cannot implement communication via SINEC H1 in parallel with the
serial interfaces.
Communication via SINEC H1 is described in detail in the CPU 948
Programming Guide.
PG Interface SI1
Interface SI2
Communication
via Parallel
Backplane Bus
with SINEC H1
CPUs, Memory Cards, Memory Submodules, Interface Submodules