Siemens S5-135U/155U appendix Special Features of the 432 Digital Input Module

Digital Input/Output Modules

8.1.3Special Features of the 432 Digital Input Module

Modes

Reaction Time

Operation without Process Alarm

Settings on the 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:

Swithout process alarm (ªnormalº digital input module)

Swith initiation of a process alarm via interrupt

Swith 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

Sthe automatic updating of the process image might acknowledge a process alarm without the system program having detected and interpreted this alarm;

Sonly 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

0.3ms, 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

1Open jumpers X3 and X4

2Set switch rows S1 and S2 to Off

		S1
	0	IR-A
	1	IR-B
	2	IR-C
	3	IR-D
	4	IR-E
	5	IR-F
:OFF	6	IR-G
:ON	7	INT

S2

0

1

2

3

4

5

6

7

Bit 0 Bit 1

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

Figure 8-3 Switch Settings for Operation without Process Alarm

The setting for switch row S3 is arbitrary in this mode.

8-8	System Manual
	C79000-G8576-C199-06