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Yaskawa Sigma II/III Serial Absolute Encoder

This section provides wiring instructions for a Yaskawa motor equipped with a Yaskawa Sigma II/III Serial Absolute Encoder. The encoder can have 16-bits (Sigma II), 17-bits (Sigma II/III) or 20-bits (Sigma II/III) of resolution per revolution plus a battery backed-up multiple turns counter. This encoder transmits its position as a serial bit stream via RS-485 lines instead of A-B incremental pulses.

Due to the additional capabilities needed to process the absolute encoder signal, these encoders may require the "Enhanced" versions of the Guidance Controllers. Please contact Brooks for the current hardware requirements for interfacing to these types of encoders.

For information on configuring this type of encoder, please see the Software Setup section of the Controller Software section of the PreciseFlex Library.

In addition to the Encoder Connections in Table 23-12, please review the Installation Information for important recommendations on the use of twisted pair wires and shield grounding.

Table 23-13 shows the wiring instructions for the Motor Power Connectors.

For the multi-turn counter to operate properly, a battery must be connected to the Absolute Encoder Battery Connector on the MCIM/MIDS3 board. Please see the information on that connector for detailed pin outs and plug types. Table 23-14 contains information on the required battery power.

NOTE: Unlike other absolute encoders, the Sigma II/III does not have an internal battery or capacitor that can retain the multi-turn data. Therefore, if the external battery is disconnected while the controller's power is off or the cable from the controller to the encoder is disconnected at anytime, the multi-turn data will be lost and the absolute position of the motor and encoder will have to be reestablished.