Digital Modules
4-36 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
4.10.1 Assigning Parameters to the SM 421; DI 16 24 VDC
Parameter Assignment
You will find a description of the general procedure for assigning parameters to
digital modules in Section 5.7.

Parameters of the SM 421; DI 16 24 VDC

You will find an overview of the parameters you can set and their default settings

for the SM 421; DI 16 24 VDC in the table below.

Table 4-13 Parameters of the SM 421; DI 16 24 VDC
Parameter Value Range Default2) Parameter
Type Scope
Enable
•Diagnostic interrupt1)
•Hardware interrupt1) Yes/no
Yes/no No
No Dynamic Module
•Destination CPU for
interrupt 1 to 4 –Static Module
Diagnostics
•Wire break
•No load voltage
L+/sensor supply
Yes/no
Yes/no No
No Static Channel
Channel
group
Trigger for hardware
interrupt
Dynamic
Channel
•Rising edge
•Falling edge
Yes/no
Yes/no
– Dynamic Channel
Input delay 3 ms (DC)
0.1 ms (DC)
0.5 ms (DC/AC)
3 Static Channel
group
Reaction to Error Substitute a Value (SV)
Keep Last Value (KLV) SV Dynamic Module
Enable substitute value “1” Yes/no No Dynamic Channel
1( If you use the module in ER-1/ER-2, you must set this parameter to “No” because the interrupt lines are not
available in ER-1/ER-2.
2( Only in the CC (central controller) is it possible to start up the digital modules with the default settings.

Assignment of the Encoder Supplies to Channel Groups

The two encoder supplies of the module are used to supply two channel groups:

inputs 0 to 7 and inputs 8 to 15. In these two channel groups, you parameterize the

diagnostics for the encoder supply, too.