Knowledge base Automation Systems Machine Automation Controllers (SYSMAC)

How To Use A Synchronous Serial Interface Unit With The NJ-series CPU (CJ1W-CTS21-E, SSI Unit)

Modified on Mon, 6 Oct, 2025 at 9:19 AM

Objectives
To detail the specifications and operation of the CJ1W-CTS21 when used with the NJ-series CPU.
Overview
The CJ1W-CTS21-E counter unit provides easy connection of up to 2 Synchronous Serial Interface encoders to any CJ or NJ system. Key features include:
  • 2 Encoder inputs
  • Configurable to accept all known variations of Synchronous Serial Interface protocols
  • Fully configurable SSI communication parameters per channel
  • Easy wiring

Please note that the data transfer from the SSI encoder with the NJ CPU is not synchronised with the EtherCAT cycle.

Version Support

The CJ1W-CTS21-E unit is supported by NJ-series CPU firmware version 1.02 and higher as well as Sysmac Studio version 1.02 and higher.

Summary

In general, the CJ1W-CTS21 unit will function the same on an NJ-series controller compared to the CJ-series PLC. However, instead of memory allocation based on Machine Number settings for configuration and operation, the NJ-series uses Device Variables for these purposes. See the attachment "CJ1W-CTS21-E for NJ InstrSheet.pdf" for more information.

Attachments (1)

pdf

CJ1W-CTS21-E_for_NJ_InstrSheet.pdf
272 KB

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