Siemens S7-1500 Manual page 29

Power reduction (derating) in relation to the mounting position and ambient temperature (per module)
The following graphs show the number of channels (CHx) that can be used simultaneously in
relation to the mounting position of the S7-1500/ET 200MP automation system and the
ambient temperature.
Figure 6-1
Digital input module DI 16x24...125VUC HF (6ES7521-7EH00-0AB0)
Manual, 12/2016, A5E35681478-AC
Information on channels used simultaneously (per module):
Technical specifications
29