ALR121-S51 YOKOGAWA Serial Communication Module

YOKOGAWA ALR121-S51 Serial Communication Module

YOKOGAWA ALR121-S51 Serial Communication Module

Availability: 99 left in stock

The YOKOGAWA ALR121-S51, also cataloged as the ALR121 Serial Communication Module, operates as a dedicated hardware component for executing half-duplex...

SKU: ALR121-S51

Manufacturer: Yokogawa
Product No.: ALR121-S51
Product Type: Serial Communication Modules
Product Origin: JAPAN
Payment:T/T, Western Union
Weight: 340g
Shipping port: Xiamen
Warranty: 12 months

Description Reviews

The YOKOGAWA ALR121-S51, also cataloged as the ALR121 Serial Communication Module, operates as a dedicated hardware component for executing half-duplex serial data transmission and field device interfacing within CENTUM VP / CS 3000 Field I/O platforms. The hardware establishes connection methods via point-to-point RS-422 or multipoint RS-485 four-wire systems utilizing start-stop synchronization. Operating at transmission speeds ranging from 1200 bps to 38400 bps, the module processes physical signal conversions and routes electrical commands directly to the system backplane bus.

Hardware Specifications

Parameter	Specification
Model	ALR121-S51
Brand	YOKOGAWA
Origin	JAPAN
Weight	0.34 kg
Dimensions	107.5 x 130 x 32.8 mm
Operating Temp	-20 to +70 deg C
Power Consumption	300 mA at 5 VDC / 20 mA at 24 VDC
Interface Type	RS-422 / RS-485 (4-wire system)
Communication Function	Half-duplex
Synchronization Method	Start-stop synchronization
Transmission Speed	1200 / 2400 / 4800 / 9600 / 19200 / 38400 bps
Number of Channels	16 isolated channels
Isolation Voltage	1500 VAC for 1 minute (Channel to system)
Corrosion Protection	ISA G3 conformal coating

Process Control and DCS Instrumentation Features

The module integrates specialized channel-to-channel isolation parameters to mitigate ground loop noise across the distributed control network. This physical isolation baseline ensures that voltage spikes or signal degradation on one serial loop cannot propagate to adjacent processing channels or compromise backplane communications. Furthermore, the embedded circuitry is hardened against high electromagnetic interference (EMI) and radio frequency interference (RFI), maintaining synchronous data integrity under transient industrial noise profiles without requiring external isolation barriers.

Frequently Asked Questions

Q: Does the module support hot-swap replacement within an active FIO subsystem?

A: Yes, the hardware incorporates online hot-swap capabilities, allowing terminal removal and module extraction from the FIO baseplate without interrupting the power supply or communication loops of adjacent modules.

Q: What are the continuous backplane current limitations for this unit?

A: The device draws a maximum stable current of approximately 300 mA from the 5 VDC backplane logic rail and 20 mA from the 24 VDC field rail during peak active execution.

Field Installation Guidelines

Mounting and Orientation: Secure the module vertically onto the dedicated FIO baseplate slot. Ensure the dual-latch engagement mechanisms click completely into place to verify rigid electrical contact with the backplane connector.
Shielding and Grounding: Terminate all RS-422 and RS-485 serial communication cable shields at a single, dedicated instrumentation ground point. Do not create loops by grounding shield lines at both ends of the run.
Wiring Separations: Route all low-voltage signal wiring through separate cable trays or conduits distinct from high-voltage AC power lines to minimize induced noise. Maintain a minimum separation distance of 300 mm from motor supply lines.

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