Siemens Simatic S7-400 - Manual (Page 169)

Digital Modules
4-47
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
4.12.1 Assigning Parameters to the SM 421; DI 16 24/60 VUC
Parameter Assignment
You will find a description of the general procedure for assigning parameters to
digital modules in Section 4.3.
Parameters of the SM 421; DI 16 24/60 VUC
The following table contains an overview of the parameters you can set and their
default settings for the SM 421; DI 16
24/60 VUC.
Table 4-16 Parameters of the SM 421; DI 16 24/60 VUC
Parameter Value Range Default 2) Parameter
Type
Scope
Enable
•
Diagnostic interrupt 1)
•
Hardware interrupt 1)
Yes/no
Yes/no No
No Dynamic Module
•
Destination CPU for interrupt 1 to 4 – Static Module
Diagnostics
•
Wire break Yes/no No Static Channel
Trigger for hardware interrupt
•
Rising (positive) edge
•
Falling (negative) edge
Yes/no
Yes/no
– Dynamic Channel
Input delay 3) 0.5 ms (DC)
3 ms (DC)
20 ms (DC/AC) 3 (DC) Static Channel group
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.
3) If you assign 0.5 ms , then you should not parameterize a diagnosis because the internal processing time
for diagnostic functions can be > 0.5 ms.
Ensuring a Wire Break Check Is Carried Out
To ensure that a wire break check is carried out, you require an external sensor
circuit using a resistor of 18 to 56 k
W.
The resistor should be connected parallel to
the contact and should be arranged as closely as possible to the sensor.
This additional resistor is not required in the following cases:
• If two-wire BEROs are used
• If you don’t parameterize the “Wire Break” diagnosis