Siemens S5-135U/155U appendix Via IB, Switch S2, PW128 Load I/O word, PW130 Etc

Digital Input/Output Modules

		S1		S2
	0	IR-A	0	Bit 0
	1	IR-B	1	Bit 1
	2	IR-C	2	Bit 2
	3	IR-D	3	Bit 3
	4	IR-E	4	Bit 4
	5	IR-F	5	Bit 5
: OFF	6	IR-G	6	Bit 6
: ON	7	INT	7	Bit 7

S3

0

1

2

3

4

5

6

7

}Byte 3

}

Byte 2

}Byte 1

}

Byte 0

Process Interrupt via IR-C

Byte 0: Positive-Going Edge

Byte 1: Negative-Going Edge-

Byte 2: Both Edges

Byte 3: No Process Interrupt

Figure 8-4 Switch Settings for Operation with Process Alarm via Interrupt (Example)

Operation with In this mode, a process alarm is initiated via input byte IB 0. This mode is

Process Alarm only possible in conjunction with a CPU 948 in single-processor operation.

via IB 0

To operate the 432 digital input module with process alarm via IB 0, you can insert it at any I/O slot.

When you use the module in the CC, you must not set any other input module to address 0 (i.e. neither in the normal (P) nor in the extended (O) area).

If you use the module in an EU which is addressed in the normal area, you must not set any other input module in the EU to address 0 in the normal area.

So that the module can initiate a process alarm for a change of logic state, the alarm must be processed by an alarm routine (alarm OB) in the user program, with automatic acknowledgement of the alarm. To avoid loss of an alarm, it must not be possible for the alarm OB to be interrupted by process alarms. The CPU must process the process alarms with level triggering (see Programming Guide of the CPU).

Scanning the	Example:
Process Inputs	Program the following in the alarm OB which you have preset with byte IB 0
	and switch S2:

L	PW128	(load I/O word)
T	FW0	(transfer flag word)
L	PW130	etc.
T	FW2

8-10	System Manual
	C79000-G8576-C199-06