Encoder Identification For Ssi Encoders Without Incremental Tracks - Siemens Sinamics s120 Commissioning Manual

Commissioning
3.19 Commissioning of SSI encoders
Diagnostics
Example 1
An SSI encoder without incremental tracks is used. The encoder has a singleturn resolution
of 16 bits and a multiturn resolution of 14 bits. The fine resolution p0418[x] and p0419[x] is
set to the value 2. In parameter r0482[x] (X_IST1), the product is formed from "pulses per
revolution" and fine resolution p0418[x]. If using SSI encoders without incremental tracks, the
number of pulses and singleturn resolution are identical. In our example, the actual position
value X_IST1 (r0482[x]) must therefore have changed by the following value after one
encoder revolution:
Single turn resolution * fine resolution = 2
Example 2
An SSI encoder with incremental tracks is used. In this case, incorrect SSI protocol settings
can be seen, e.g. by the fact that once the system has been switched on a different absolute
position is indicated from that before it was last deactivated.
The absolute position X_IST2 (r0483[x]) must be considered by way of a check. Following
PROFIdrive, however, just one value is displayed in this parameter if bit 13 (request absolute
value in cycles) is set to the value 1 in the encoder control word p0480[x].
This bit can be set, e.g. with the aid of the binector-connector converter.
Once switched on, the SSI encoder is now turned a few revolutions. Once switched off and
on again, the absolute position of X_IST2 (r0483[x]) must indicate an unchanged value. Only
minor deviations may occur in the fine resolution area.
3.19.2

Encoder identification for SSI encoders without incremental tracks

The SSI (Synchronous Serial Interface) is used to transfer the absolute value for absolute
value encoders. Because the data transfer format is not standardized for SSI, the
manufacturers of encoder systems can define the format themselves. Consequently, a
universal parameterization of SSI encoders was introduced for the SINAMICS drive system
so that the largest possible number of different encoders and manufacturers are supported.
The encoder identification for SSI encoders simplifies the encoder configuring. Two different
techniques are available for the encoder identification.
Moving the axis manually
The manual technique is particularly suitable for easily accessible axes as well as rotary
axes without a holding brake.
For this technique, the axis must be turned or moved using a defined movement. For a rotary
encoder, this movement corresponds to one encoder revolution. For a linear encoder, it is
25 mm.
Precondition
The encoder/motor must be easily accessible and it must be possible to rotate the axis
(released brake).
278
16 2
* 2 = 262144
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Commissioning Manual, (IH1), 07/2016, 6SL3097-4AF00-0BP5