Technical data

Commissioning
2.14 Notes on commissioning SSI encoders
Commissioning Manual
Commissioning Manual, (IH1), 01/2011, 6SL3097-4AF00-0BP1
147
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
evaluation
through module
Incremental tracks Absolute position Power supply for
encoder
SSI baud rate Remarks
SMC20 sin/cos, 1 Vpp SSI not cyclic
1)
5 V 100 kBaud -
SME25 sin/cos, 1 Vpp SSI not cyclic
1)
5 V 100 kBaud SME25 is only
suited to direct
measuring
systems
SMC30 Square or
no incremental
tracks
SSI not cyclic
1), 3)
SSI, cyclic
2)
5 V or 24 V 100-
250 kBaud
-
1)
"not cyclic" means that the absolute position is only read when initializing the Sensor Module, after which the position is
only calculated by the incremental tracks.
2)
"cyclic" means that the absolute position is read permanently (usually in the PROFIBUS or position controller cycle) and
the position (X_IST1) formed from this.
3)
the SSI protocol is cyclically read-out for the plausibility checks
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
waiting period of 800 ms.
● After the waiting period has expired, clock signals are applied to the clock cable and the
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.
● If the encoder has not ramped up after approx. 10 seconds, the encoder evaluation
module signals a timeout error.