Siemens S5-135U/155U System Manual page 184

CPUs, Memory Cards, Memory Submodules, Interface Submodules
Second Interface
You can optionally use the second interface of the CPU 928B as:
SI2
To utilize the second interface as the PG interface, you need the
You need one of the following interface submodules for the RK 512
computer link, for data transmission with procedures 3964/3964R and for
data transmission with the "open driver":
To utilize the second interface for data transmission via the SINEC L1 bus,
you need the
The CPU 928B is delivered without an interface submodule. You can operate
the CPU 928B without an integral interface submodule. The opening to
accept a submodule in the front plate is closed by a cover. Only remove the
cover to fit an interface submodule.
A description of interface submodules can be found in Section 5.11, and the
order numbers in the ordering information.
A detailed description of the second interface can be found in the CPU 928B
Communication Manual.
Process Interrupt
There is an interrupt line in the PLC for each CPU. It can be used when the
Processing
reaction to an event must occur with higher priority than the reaction to other
events.
To process an interrupt, cyclic program processing is interrupted and the
program stored in OB 2 (OB for interrupt processing) is inserted.
(Refer to the CPU 928B Programming Guide for further details.)
This interrupt-driven program processing is only possible using an
interrupt-capable digital input module or a suitable operating CP/IP module.
No jumper setting on the CPU 928B is required. Please note, however, that
the usable interrupt line on the backplane bus depends on the CPU slot and
must be set accordingly on the I/O module (see Section 4.1).
5-44
A PG interface (for PG and operator panels)
Interface for the RK 512 computer link
Interface for data transmission with procedures 3964/3964R
Interface for data transmission with the "open driver"
Interface for data transmission via the SINEC L1 bus (from Version 6ES5
928-3UB12).
PG submodule.
V.24 submodule (RS 232C)
TTY submodule
RS422 A/485 submodule (only in the RS422 A module).
SINEC L1 submodule (from Version 6ES5 928-3UB12).
System Manual
C79000-G8576-C199-06