Notes On The Commissioning Of A 2-Pole Resolver As Absolute Encoder - Siemens SINAMICS S120 Commissioning Manual

Commissioning

2.15 Notes on the commissioning of a 2-pole resolver as absolute encoder

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 after an encoder resolution by the
value
singleturn resolution * fine resolution = 2^16 * 2^2 = 262144
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.
2.15 Notes on the commissioning of a 2-pole resolver as absolute
encoder
Description
You can use 2-pole (1 pole pair) resolvers as singleturn absolute encoders. The absolute
encoder position actual value is provided in Gn_XIST2 (r0483[x]).
Actual position value format
The factory setting for the fine resolution of Gn_XIST1 differs from the fine resolution in
Gn_XIST2 (p0418 = 11, p0419 = 9). This may cause a slight displacement of the encoder
position after switching the drive unit off/on.
Therefore, when using a 2-pole resolver as an absolute encoder, we recommend that the
fine resolution for Gn_XIST1 (p0418) is set the same as the fine resolution for Gn_XIST2
(p0419), e.g. p0418 = p0419 =11.
2-pole resolvers are automatically entered in the PROFIdrive profile (r0979) as singleturn
absolute encoders.
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Commissioning Manual, (IH1), 01/2012, 6SL3097-4AF00-0BP2
Commissioning Manual