Siemens SIMATIC S7-1500 Manual page 32

Block diagram
You must ground the shields of the cables between encoder and technology module both
through the shield support at the front connector (shield bracket and terminal) and at the
encoder.
The figure below shows the block diagram of the technology module with one connected TTL
incremental encoder.
①
Electrical isolation
②
Encoder supply, optionally 5 V DC or 24 V DC, according to the specification of the encoder manufacturer
③
Technology and backplane bus interface
④
Shield support at the front connector
⑤
Input filter
⑥
Supply voltage via power supply element
⑦
Equipotential bonding
⑧
RS422 incremental encoder
Figure 3-4 Block diagram with TTL incremental encoder
Technology module TM PosInput 2 (6ES7551-1AB00-0AB0)
Manual, 06/2018, A5E03982218-AB
Wiring
3.3 TTL encoder signals
31