Siemens SIMATIC S7-1500 Manual page 12

Wiring
3.1 Wiring and block diagram
Abbreviations used
Meaning of the abbreviations used in the following figure:
M
CHx
The figure below shows you how to connect the module and the assignment of the channels
to the addresses (input byte a to input byte d).
①
Figure 3-1
12
Ground connector
Channel or display for the channel status
Backplane bus interface
Block diagram and terminal assignment
Digital input module DI 32x24VDC BA (6ES7521-1BL10-0AA0)
Manual, 09/2014, A5E32363711-AB