Features:
- Supports point-to-point and multipoint connections over 1200 meters.
- Enables data exchange with external Modbus masters and sequencers.
- No interference with safety loops in Yokogawa safety control systems.
The ALR121-S00 S1 features an RS-422/RS-485 (4-wire system) interface that supports both point-to-point (RS-422) and multipoint (RS-485) connection methods. This flexibility allows the ALR121-S00 S1 to communicate with a single device in RS-422 mode or with multiple devices in RS-485 mode. With transmission speeds from 1200 to 38400 bps and a maximum transmission distance of 1200 meters, the ALR121-S00 S1 is suitable for large-scale industrial installations. The half-duplex communication and start-stop synchronization ensure reliable data transfer.
The ALR121-S00 S1 provides both Modbus slave communication and subsystem communication functions. The Modbus slave function allows external Modbus master systems to access SCS data, enabling integration with separate systems. The subsystem communication function enables data exchange with sequencers and other devices. The ALR121-S00 S1 uses binary transmission code with 8-bit character length, 1/2 stop bits, and none/even/odd parity options. The 1 ms lag time after data transmission ensures proper timing.
The ALR121-S00 S1 is an interference-free module that has no interference with the safety loop, ensuring the integrity of safety functions. It mounts on SSC60□, SSC50□, SSC57□, SSC10□ safety control units, and SNB10D safety node units connected via ESB bus. The ALR121-S00 S1 runs on CFS1300 (SSC60□), CFS1100 (SSC50□/SSC10□), and CFS1170 (SSC57□) control functions. Engineering work is performed with CHS5100 Safety System Generation and Maintenance Function Package.
The ALR121-S00 S1 YOKOGAWA Communication Module may still be available for purchase and support from Apter Power beyond
End-Of-Life (EOL) by the manufacturer (OEM).
YOKOGAWA ALR121-S00 S1 Communication Module Manuals,
Datasheets, Drivers, Link
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not
included with this equipment unless listed in the above stock item description. All prices are
shown in USD.
YOKOGAWA ALR121-S00 S1 Communication Module Specs
General
- Manufacturer YOKOGAWA
- Model ALR121-S00 S1
- Condition New Original ready stock
- Product Family
ALR121-S51 S1,ALR121-S50 S1,ALR121-S50,ALR121-S51
Important Notice: Other accessories, manuals, cables, calibration data, software, etc. are not
included with this equipment unless listed in the above stock item description. All prices are
shown in USD.
- Subsystem Integration: Connects the main DCS directly to auxiliary package systems, such as Programmable Logic Controllers (PLCs) managing packaging lines, water treatment skids, or compressor controls.
- Specialized Analytical Monitoring: Links to plant analyzer equipment, including gas chromatographs, continuous emissions monitoring systems (CEMS), and custody transfer flow meters.
- Emergency Systems Readout: Monitors status tags from independent emergency shutdown systems (ESD) or fire & gas (F&G) logic solvers for display on the main operator console.
- Physical Interface Ports: Features two independent serial ports configured for RS-422 (4-wire) or RS-485 (2-wire) physical layer standards. Communication lines are wired using dedicated D-sub or terminal block adapter assemblies.
- Protocol Support: Supports industry-standard Modbus RTU (Master/Slave) and ASCII protocols right out of the box, handling multi-node arrangements with up to 31 downstream slave devices per port.
- Baud Rates and Distances: Handles standard transmission velocities ranging from 1200 bps up to 38400 bps, covering physical cable loop lengths of up to 1200 meters over high-quality shielded twisted-pair (STP) lines.
- Port-to-Port Galvanic Isolation: Each communication port is built with heavy internal optocouplers and electrical isolation barriers. This stops physical field electrical surges, ground loops, or high lightning-induced transient voltages from burning out the card or traveling back into the main DCS CPU backplane.
- Electromagnetic Compatibility (EMC): Complies with CE marking and C-Tick rules for noise immunity. It ignores heavy electromagnetic emissions from surrounding large motors or switchgears and emits zero interference into adjacent DCS processing loops.
- Hazardous Location Certifications: Satisfies FM (Factory Mutual), CSA, and ATEX/IECEx Zone 2 / Class I, Div 2 compliance requirements, certifying it for safe placement inside sealed industrial enclosures close to hazardous processing sections.