Yokogawa ALR111-S51 Serial Communication Module

Configured for serial data integration in N-IO/FIO platforms, the Yokogawa ALR111-S51 (ALR111 Serial Communication Module) provides direct physical/electrical execution of RS-232C communication protocols and network traffic management between field devices and the system bus.

Suffix Breakdown & Model Matrix

• ALR111: Base model identifier for the 2-port Serial Communication Module.
• -S: Standard type configuration.
• 5: No explosion protection rating.
• 1: Compliance with ISA Standard G3 for corrosive environments.

Hardware Specifications

Yokogawa DCS Process Control Characteristics

• Channel-to-Channel Isolation: The module features galvanic isolation between the two RS-232C ports and the internal system backplane, preventing potential ground loops and signal interference when communicating with multiple discrete field devices.
• 4-20 mA HART Loop Protocol: While the module primary function is serial communication, the architecture supports data throughput for systems utilizing HART-to-RS-232 gateways, ensuring consistent diagnostic data delivery to the Centum VP supervisory level.
• Cold Junction Compensation (CJC): The module assembly utilizes low-drift components that minimize thermal sensitivity, preserving signal integrity when installed in high-density instrumentation cabinets.
• System Integration: The module utilizes a deterministic communication controller to manage serial frame processing, ensuring that asynchronous data from connected field sensors remains aligned with the system bus scan cycles.

Frequently Asked Questions

Q: Does the ALR111-S51 support RS-485 conversion?

A: No, this specific model is hardwired for RS-232C communication. Conversion to RS-485 or other standards would require an external industrial signal converter.

Q: Is this module compatible with hot-swapping under normal operational conditions?

A: Yes, the module supports hot-swapping within the N-IO/FIO node chassis. Ensure that the associated software configuration is correctly mapped to the new module address before system activation.

Field Installation Guidelines

• Mounting: Seat the module into the designated slot on the N-IO/FIO node. Tighten the top and bottom retaining screws to establish a secure electrical bond with the node chassis for EMI protection.
• Wiring: Use shielded RS-232C serial cables with lengths not exceeding standard EIA/TIA specifications to maintain signal quality. Terminate cable shields at the designated ground terminals to prevent noise pickup.
• Environmental: While the module is ISA G3 rated for corrosion resistance, maintain the control cabinet environment within the specified temperature range to ensure component longevity.
• Diagnostics: Upon installation, monitor the front-panel status LEDs. An active communication link will be indicated by the flashing TX/RX LEDs, confirming proper handshake and data flow with the field device.