Siemens S5-135U/155U - Manual (Page 320)

8-8
System Manual
C79000-G8576-C199-06
8.1.3 Special Features of the 432 Digital Input Module
The 432 digital input module accepts 32 process signals and emits a process
alarm if the logic state at one of its inputs changes.
You can operate the module in the following modes:
S
without process alarm (“normal” digital input module)
S
with initiation of a process alarm via interrupt
S
with initiation of a process alarm via IB 0 (only in conjunction with
CPU 948)
To operate the module with process alarm via IB 0, you must address it in the
normal (P) area from byte 128 because
S
the automatic updating of the process image might acknowledge a process
alarm without the system program having detected and interpreted this
alarm;
S
only modules addressed in the normal (P) area can initiate a process
alarm via IB 0.
The time for reaction of the module to a process alarm is mainly determined
by the input circuitry. You can set the reaction time to one of the values
0.3 ms, 1 ms or 3 ms with switch S5. Note that the filtering effect decreases
with shorter reaction times, and interference may be received as useful
signals (effect of the line length, see the technical specifications).
To operate the module without process alarm, you can insert it at any slot for
I/O modules and address it in the entire I/O area. If you address it in the area
PB/PY 0 to PB/PY 124, it will be within the automatic updating of the
process image.
Make the following settings on the module to operate it without process
alarm:
Step Action
1 Open jumpers X3 and X4
2 Set switch rows S1 and S2 to Off
S1
3 3 Bit 3 IR-D
4 4 Bit 4 IR-E
5 5 Bit 5 IR-F
6 6 Bit 6 IR-G
7 7 Bit 7 INT
0 0 Bit 0 IR-A
1 1 Bit 1 IR-B
2 2 Bit 2 IR-C
:OFF
:ON
S2
Figure 8-3 Switch Settings for Operation without Process Alarm
The setting for switch row S3 is arbitrary in this mode.
Modes
Reaction Time
Operation without
Process Alarm
Settings on the
Module
Digital Input/Output Modules