Omron CJ1W-SCU31-V1 CJ Series Serial Communications Unit 2 x RS-422A/485

Omron CJ1W‑SCU31‑V1 is a CPU Bus Unit for SYSMAC CJ‑series PLC systems. Provides two independent RS‑422A/485 serial ports for connecting external devices such as HMIs, barcode readers, serial printers, temperature controllers and drives. Supports multiple serial communication protocols configurable per port: Protocol Macro, Host Link, NT Link (1:N mode), Serial Gateway, No‑protocol, and Modbus‑RTU Slave. DIN rail mounting, 31 mm width.

Applications:

• RS‑422A/485 serial connection to HMIs, SCADA systems and host computers

• Integration of barcode readers, serial printers, weigh scales and instrumentation

• Data exchange with third‑party devices (inverters, temperature controllers, drives)

• Legacy system upgrades requiring additional RS‑422A/485 ports for CJ‑series PLCs

Technical Specifications:

Core Specifications

• Product type: CJ‑series CPU Bus Unit (Serial Communications Unit)

• Number of ports: 2 (configurable per port)

• Interface 1: RS‑422A/485 (maximum transmission distance 500 m)

• Interface 2: RS‑422A/485 (maximum transmission distance 500 m)

• Serial protocols: Protocol Macro, Host Link, NT Link (1:N mode), Serial Gateway, No‑protocol, Modbus‑RTU Slave, loopback test (configurable per port)

• Transmission speed: 1,200/2,400/4,800/9,600/19,200/38,400/57,600/115,200/230,400 bps (default 9,600 bps)

• Number of mountable units: up to 16 (including all other CPU Bus Units)

• Mounting location: CPU rack or expansion rack (no restrictions on mounting location except when external interrupt tasks are used)

• Simple Backup Function: backup of Protocol Macro data to CPU Unit Memory Card

• Interrupt notification function: available in No‑protocol mode (external interrupt task executed when data is received)

• Unit numbers allocated: 1 (rotary switch setting 0‑F)

• Current consumption (5 V DC): 380 mA max.

• Dimensions (W × H × D): 31 mm × 90 mm × 65 mm

• Weight: 110 g max.

• Operating temperature: 0 °C … 55 °C

• Storage temperature: –20 °C … +75 °C

• Certifications: UC1, N, L, CE

Advanced Specifications

• Communications mode: half‑duplex (full‑duplex for slave‑initiated communications)

• Synchronous mode: start‑stop synchronization (asynchronous mode)

• Protocol Macro function: user‑defined communication sequences for custom protocols

• Serial Gateway function: CompoWay/F, Modbus‑RTU, Modbus‑ASCII, and Host Link protocol conversion

• Host Link: C‑mode and FINS commands

• No‑protocol mode: user‑defined data format for custom ASCII/binary transmission (external interrupt task supported)

• Unit Ver. 1.3 or later supports Modbus‑RTU slave mode

• Data exchange with CPU Unit: 25 words allocated in CPU Bus Unit CIO Area (constant data exchange); each port allocated 10 words in CPU Bus Unit DM Area (total 20 words)

• When an NT‑AL001 RS‑232C/RS‑422A conversion unit is used, current consumption increases by 0.15 A per unit

System Integration:

• This serial communications unit belongs to the Omron SYSMAC CJ series.

• Compatible with CJ1, CJ2, CS1, NJ, NSJ series CPU units and CP1H systems.

• Installs on CPU rack or expansion rack via CJ I/O Bus.

• One unit number is allocated (rotary switch 0‑F); occupies 25 words in the CPU Bus Unit CIO Area (constant data exchange with CPU Unit) and 20 words in the CPU Bus Unit DM Area (10 words per serial port).

• Configuration performed in CX‑Programmer (I/O Table and Unit Setup).

• For detailed installation, configuration and protocol setup, refer to the product hardware manual.

Related Products:

• CJ1W‑SCU41‑V1 – 1 × RS‑232C + 1 × RS‑422A/485 ports (SCU31‑V1 is the all‑RS‑422/485 version)

• CJ1W‑SCU21‑V1 – 2 × RS‑232C ports

• CJ1W‑CIF11 – RS‑422A/485 adapter for serial port expansion

• CJ1W‑PA205R – Power supply unit for CJ‑series CPU rack

• CX‑Programmer – Programming and configuration software for CJ‑series PLCs