Siemens Simatic S7-400

You enable a parameter by setting a logical "1" at the corresponding bit.
Table A-4 Data record 1 for parameters of digital input modules
Byte Bit Meaning
Byte 4 7 On falling edge at channel 15
6 On falling edge at channel 14
5 On falling edge at channel 13
4 On falling edge at channel 12
3 On falling edge at channel 11
2 On falling edge at channel 10
1 On falling edge at channel 9
0 On falling edge at channel 8
Byte 5
Substitute value
1
7 Enable substitute value 1 on channel 7
6 Enable substitute value 1 on channel 6
5 Enable substitute value 1 on channel 5
4 Enable substitute value 1 on channel 4
3 Enable substitute value 1 on channel 3
2 Enable substitute value 1 on channel 2
1 Enable substitute value 1 on channel 1
0 Enable substitute value 1 on channel 0
Byte 6
Substitute value
1
7 Enable substitute value 1 on channel 15
6 Enable substitute value 1 on channel 14
5 Enable substitute value 1 on channel 13
4 Enable substitute value 1 on channel 12
3 Enable substitute value 1 on channel 11
2 Enable substitute value 1 on channel 10
1 Enable substitute value 1 on channel 9
0 Enable substitute value 1 on channel 8
1
Only for 6ES7 421-7BH0x-0AB0
Parameter sets of signal modules
A.2 Parameters of digital input modules
S7-400 Automation System Module Data
Reference Manual, Ausgabe 11/2016, A5E00850736-08 399