In general, for s7-1200 modules with multiple and paired L and M terminals, like 1L/1M, 2L/2M, they represent a group of I/O that be collectively sink or source depending on how 1L and 1M are wired.  So, 1L/1M in 1L to + and 1M to - terminals of DC supply, and 2L to - and 2M to + terminals of DC supply are allowed.  Just be sure all the devices in each group (or bank) are of the same type and match how their L and M are wired.

Mickey_2022

I read the datasheet of 6ES7214-1BG40-0XB0

What does it mean by "Source/sink input = Yes" ?

Does this mean I can use both sourcing and sinking configurations? Does this mean that 1M can be connected to either the positive or the negative of the power supply? (And of course, the inputs will be connected to the other terminal of the power supply).

Or Does this specify the type of the device itself? So maybe Source/sink means that I should connect 1M only to the negative terminal of the power supply. And maybe for other devices, I may find Sink/Source which means that I should connect 1M only to the positive terminal of the power supply?!

I'm just trying to guess but I need a confirmation from you, please.

Hi,

there exists also a FAQ for the topic

What is the meaning of the terms "sinking" (German: "P-lesend") and "sourcing" (German: "M-lesend") in digital modules of SIMATIC?

Regards,

Towome