Siemens S120 - Page 375

Supplementary system components and encoder system integration
8.1 Sensor Modules
AC Drive
Manual, (GH6), 04/2014, 6SL3097-4AL00-0BP4
375
Table 8- 19 Encoders that can be connected
X520
(SUB-D)
X521
(terminal)
X531
(terminal)
Track
monitoring
Remote Sense
2)
HTL bipolar 24 V
Yes
Yes
Yes
no
HTL unipolar 24 V
1)
Yes Yes (however, a bipolar
connection is recommended)
1)
no no
TTL bipolar 24 V
Yes
Yes
Yes
no
TTL bipolar 5 V
Yes
Yes
Yes
At X520
SSI 24 V/5 V
Yes
Yes
no
no
TTL unipolar
no
1)
Because the physical transmission media is more robust, the bipolar connection should always be used. The unipolar
connection should only be used if the encoder type does not output push-pull signals.
2)
A controller compares the encoder system supply voltage - sensed via the Remote Sense cables - with the reference
supply voltage of the encoder system, and adjusts the supply voltage for the encoder system at the output of the sensor
module until the required supply voltage is obtained directly at the encoder system (only for 5 V encoder system power
supply).
Maximum encoder cable lengths
Table 8- 20 Maximum encoder cable length
Encoder type
Maximum encoder cable length in m
TTL
1)
100
HTL unipolar
2)
100
HTL bipolar
300
SSI
100
3)
1)
For TTL encoders at X520 → remote sense → 100 m
2)
Because the physical transmission media is more robust, the bipolar connection should always be
used. The unipolar connection should only be used if the encoder type does not output push-pull
signals.
3)
See the diagram "Maximum cable length depending on the SSI baud rate for SSI encoders"