Siemens SINAMICS S120 Commissioning Manual page 101

Encoder Incremental tracks
evaluation
through module
SME25 sin/cos, 1 Vpp
SMC30 Square or
no incremental
tracks
CU310 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.
As of HW 6SL3055-0AA00-5CA2 and FW 2.5 SP1, the SSI protocol is read in cycles for 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
The waiting period starts again when:
● The 5 V power supply is applied to the encoder.
● Switchover to 24 V power supply after completed ramp-up of the encoder evaluation in
Commissioning
Commissioning Manual, (IH1), 07/2007 Edition, 6SL3097-2AF00-0BP7
Absolute position
SSI not cyclic
SSI not cyclic
SSI, 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.
accordance with the parameterized voltage level.
2.11 Notes on commissioning SSI encoders
Power supply for
encoder
5 V
1)
5 V or 24 V
1), 3)
2)
5 V or 24 V
2)
Commissioning
SSI baud rate Remarks
100 kHz SME25 is only
suited to direct
measuring
systems
100-250 kHz -
100-250 kHz -
101