Hello SIOS Forum Community

The synchronous serial interface (SSI) is an interface for absolute encoders (position measuring systems). It makes it possible to obtain absolute information about the position through serial data transmission.

The evaluation of SSI absolute encoders (Gray coded) could be realised, for example, with the TM_PosInput1 module (6ES7138-6BA01-0BA0) for the ET200SP.

It offers a counting channel for differential input signals to RS422 up to 1 MHz, as well as position detection using SSI absolute encoders.

For the counting functions, it is also possible to connect 5V TTL signals, but the ET200SP module for TTL encoders does not have a 5V power supply; this must be provided externally.

Manual SIMATIC ET 200SP TM PosInput 1

Another solution is the use of the module

TM_PosInput2 (6ES7551-1AB00-0AB0) for the

SIMATIC S7-1500 / ET200MP.

The TM PosInput 2 counting and position detection module has 2 identical channels for connecting pulse generators, incremental or absolute position generators according to the RS422 standard.

For counting functions, 5V TTL signals can also be used. For the ET200MP there is a corresponding contact for the 5V.

Manual SIMATIC S7-1500 TM PosInput 2

Best regards,

SIMATIC International Technical Support Hub