Siemens SINAMICS S120 Commissioning Manual page 425

Parameters that can be set for the SSI protocol
Code
1. Here, select which code versions your encoder supports:
– Gray code; special coding of transfer signals; when transitioning from one position to
– Binary code; binary-coded transfer signals
Baud rate
1. Here, enter the baud rate for the SSI encoder.
When setting the baud rate, also take into account the update rate of the actual position
value. All bits must be transferred within the cycle, as otherwise the data transfer is too
slow or only performed every xth cycle. If you are using an SSI encoder with incremental
track, the incremental track is used for the speed control.
Example: For a baud rate of 100 kHz and an SSI length of 35 bits, 10x35 µs = 350 µs +
30 µs monoflop time = 380 µs are required to transfer the SSI value. If the current
controller cycle is faster, you must set a higher baud rate or activate the "Position value
extrapolation" option (only for pure SSI encoders).
The possible baud rate depends on the cable length (see the diagram).
Commissioning with Startdrive
Commissioning Manual, 11/2017, 6SL3097-4AA10-0BP1
another, only one bit is always changed.
A.6 Overview of measuring systems / encoders
Appendix
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