Siemens SIMATIC ET 200SP Manual page 23

L+/M supply voltage
Connect the supply voltage (DC 24V) to the L+ and M connections. An internal protective
circuit protects the technology module from polarity reversal of the supply voltage. The
technology module monitors the connection of the supply voltage.
24VDC encoder supply
To supply the encoder and sensors at the digital inputs, the technology module supplies the
DC 24V supply voltage at the 24VDC output with reference to M. Voltage is supplied from
the L+/M supply voltage and monitored for short circuits and overload.
RS422/TTL encoder signals/count signals and SSI encoder signals
The TM PosInput 1 can process either counting or SSI encoder signals. The counting
encoder signals are designated A, B and N and use either the RS422 or TTL signal
standard. The SSI encoder signals are designated DAT (letter D) and CLK (letter C) and use
the RS422 signal standard.
An encoder signal with TTL standard uses a single cable. An RS422 encoder signal uses
one cable pair and the count/SSI information is transmitted as differential voltage. This
ensures interference-free transmission of RS422 encoder signals even with high frequencies
over long distances. The RS422 line pairs must be twisted together in the cable.
You can connect the following encoder types:
● SSI absolute encoder:
● RS422/TTL incremental encoder with signal N:
● RS422/TTL incremental encoder without signal N:
● RS422/TTL pulse encoder without direction signal:
● RS422/TTL pulse encoder with direction signal:
Technology module TM PosInput 1 (6ES7138-6BA00-0BA0)
Manual, 02/2014, A5E33015755-AA
The SSI encoder signals CLK and DAT are connected via the C and D terminals. The N
terminals remain disconnected.
The encoder signals A, B and N are connected using the terminals labeled accordingly. A
and B are the two incremental signals phase-shifted by 90°. N is the zero mark signal
which returns one pulse per revolution.
The encoder signals A and B are connected via the terminals labeled accordingly. A and
B are the two incremental signals phase-shifted by 90°. The N terminals remain
disconnected.
The counting signal is connected at the A terminals. The count direction is specified via
the control interface. The B and N terminals remain disconnected.
The counting signal is connected at the A terminals. The direction signal is connected at
the B terminals. The N terminals remain disconnected.
Wiring
3.1 Pin assignment
23