Siemens SINAMICS S120 Commissioning Manual page 149

Types of encoder that can be connected
Table 2- 23 Overview of encoder types that can be connected depending on the SIEMENS evaluation module
Encoder Incremental tracks
evaluation
through module
SMC20 sin/cos, 1 Vpp
SME25 sin/cos, 1 Vpp
SMC30 Square or
no incremental
tracks
"not cyclic" means that the absolute position is only read when initializing the Sensor Module, after which the position is
1)
only calculated by the incremental tracks.
"cyclic" means that the absolute position is read permanently (usually in the PROFIBUS or position controller cycle) and
2)
the position (X_IST1) formed from this.
the SSI protocol is cyclically read-out for the plausibility checks
3)
Note
Only encoders that support a transfer rate of 100 kHz and that have a high level in idle state
may be used.
The monoflop time should be parameterized such that it is greater than or equal to the
specified monoflop time of the encoder. This must lie in the range between 15 – 30 µs.
The level during the monoflop time must be low.
Ramp-up time of the encoder
In order to ensure that correct sensor data is received, the encoder evaluation module
checks, after its own ramp-up, whether the connected encoder has also ramped up.
To do this, the SINAMICS converter system proceeds as follows:
● After the power supply is switched on at the encoder, no signals are evaluated for a
● After the waiting period has expired, clock signals are applied to the clock cable and the
● If the encoder has not ramped up after approx. 10 seconds, the encoder evaluation
Commissioning Manual
Commissioning Manual, (IH1), 01/2011, 6SL3097-4AF00-0BP1
Absolute position
SSI not cyclic
SSI not cyclic
SSI not cyclic
SSI, cyclic
waiting period of 800 ms.
response of the data line observed. As long as the encoder has not ramped up, the
encoder holds the data line permanently in the idle state (as a rule "high").
It is expected that the encoder has completed its own ramp-up by this time.
module signals a timeout error.
2.14 Notes on commissioning SSI encoders
Power supply for
encoder
5 V
1)
5 V
1)
5 V or 24 V
1), 3)
2)
Commissioning
SSI baud rate Remarks
100 kBaud -
100 kBaud SME25 is only
suited to direct
measuring
systems
100- -
250 kBaud
147