Description
Engineered for high-performance integration within industrial control architectures, the Omron CJ1W-SCU31-V1 functions as a highly versatile serial communications module within the CJ-series PLC system. This CPU Bus Unit facilitates seamless, high-speed data exchange between the CPU and external peripheral devices via dual serial interfaces. Equipped with two RS-422A/485 ports, the unit supports diverse communication protocols including Host Link, protocol macro, NT Link, and loopback testing to accommodate precise industrial networking configurations.
With firmware Unit Ver. 1.2 or later, the CJ1W-SCU31-V1 extends its capabilities to include Serial Gateway functionality, no-protocol communications, and 1:1 Host Link modes. For Modbus architectures, Unit Ver. 1.3 or later adds native Modbus-RTU slave mode support. The system architecture permits mounting up to 16 CPU Bus Units per CPU Rack or Expansion Rack, allocating 25 CIO words and 20 DM words for consistent cyclic and event-driven data transfer.
Features
- Dual RS-422A/485 serial ports optimized for balanced, long-distance communication.
- Broad protocol compatibility featuring Host Link, protocol macro, and NT Link.
- Advanced connectivity modes including Serial Gateway, no-protocol, and Modbus-RTU slave (dependent on unit version).
- Efficient backplane data exchange using 25 words in the CPU Bus Unit CIO Area.
- Dedicated DM Area allocations of 10 words per port for simplified configuration and parameter settings.
- Simple Backup Function allows backing up protocol macro data directly to the CPU Unit's memory card (supported on CJ1-H and CJ1M CPU Units).
Applications
- SCADA and HMI integration in manufacturing and assembly environments.
- Modbus-RTU device monitoring and control in utility and water treatment systems.
- Distributed control networks utilizing protocol macro configurations for proprietary serial devices.
- Material handling, warehousing, and process automation lines.
Technical Specifications
Category
Specification Parameter
| Manufacturer |
Omron |
| Part Number / Model |
CJ1W-SCU31-V1 |
| Classification |
CPU Bus Unit |
| Port 1 Interface |
RS-422A/485 |
| Port 2 Interface |
RS-422A/485 |
| Protocols (Port 1) |
Host Link, protocol macro, NT Link, loopback test |
| Protocols (Port 2) |
Host Link, protocol macro, NT Link, Serial Gateway, no-protocol, Modbus-RTU slave (Unit Ver. 1.3 or later) |
| Maximum Mountable Units |
Up to 16 Units per Rack (including other CPU Bus Units) |
| CIO Area Allocation |
25 words |
| DM Area Allocation |
20 words (10 words per port) |
| Current Consumption |
380 mA (from 5V DC backplane power supply) |
| Weight |
0.11 kg maximum |
Connections and Interfaces
| Interface Port |
Physical Standard |
Supported Connection Modes |
| Port 1 |
RS-422A/485 (2-wire/4-wire) |
Host Link, protocol macro, NT Link, loopback test |
| Port 2 |
RS-422A/485 (2-wire/4-wire) |
Host Link, protocol macro, NT Link, Serial Gateway, no-protocol, Modbus-RTU slave |
Installation Guidelines
- Always shut off the power supply to the PLC system before mounting or removing the CPU Bus Unit.
- Slide the unit securely into the designated slot on the CJ-series CPU Rack or Expansion Rack, ensuring the locking sliders are fully engaged.
- Configure terminal block connections and termination resistors according to your RS-422A/485 network topology specifications.
- Isolate communication cables from high-voltage wiring to minimize electromagnetic interference.