Eaton XN300 - 36.3 Wiring topic

36 Interface module XN-322-2SSI
36.3 Wiring topic
299 XN300 slice modules 02/24 MN050002EN Eaton.com
36.3 Wiring topic
SSI encoders can be run in two different modes:
• Binary Mode
• Gray Decoder Mode
36.3.1 Binary Mode
When using binary mode, Gray code decoding must be turned off (it is turned
off by default). This mode can also be used when the encoder delivers Gray
code data that includes unencoded extra bits, i.e., as using automatic
decoding in this case would yield an incorrect final result. In this latter case,
decoding must be carried out in the PLC program. The encoder's
deserialized data stream will be mapped to the channel's relevant data
register as a 32-bit value.
36.3.2 Gray Decoder Mode
For encoders delivering Gray code data, the result will be automatically
decoded (Gray code decoding ON) and provided as a 32-bit value in the
channel's corresponding data register. Additional bits in the encoder's data
stream must be taken into account in this mode. Automatic decoding will
result in incorrect decoding if there are additional bits that are not encoded
and that are transmitted before the encoded measurement data in the serial
data stream. In this case, using binary mode is recommended. If the
additional bits that have not been encoded instead come after the
measurement data in the encoder's serial data stream, decoding will only
result in the additional bits being corrupted.