Siemens Simatic M7-400 Reference Manual page 154

Digital Modules
4.10 Digital Input Module SM 421; DI 16
(6ES7421-7BH01-0AB0)
Characteristics
The digital input module SM 421; DI 16
• 16 inputs, isolated in 2 groups of 8
• 24 VDC rated input voltage
• Suitable for switches and two/three/four-wire proximity switches
(BEROs, IEC 61131; type 2)
• 2 short-circuit-proof sensor supplies for 8 channels each
• External redundant power supply possible to supply sensors
• "Sensor supply (Vs) O.K." status display
• Group error display for internal faults (INTF) and external faults (EXTF)
• Programmable diagnostics
• Programmable diagnostic interrupt
• Programmable hardware interrupt
• Programmable input delays
• Parameterizable substitute values in the input range
The status LEDs indicate the process status.
Note
The spare parts of this module is compatible with SM 421; DI 16
(6ES7 421-7BH00-0AB0).
To be able to use the new function "input delay 50 ms", you require STEP 7 V 5.2.
4-32
24 VDC has the following features:
S7-400, M7-400 Programmable Controllers Module Specifications
24 VDC;
DC 24 V;
A5E00069467-07