The Yokogawa ALR121-S00, also cataloged as the ALR121 Serial Communication Module, operates as a dedicated hardware component for half-duplex subsystem integration and data conversion within distributed control system (DCS) architectures.
Suffix Breakdown & Model Matrix
The ALR121 series utilizes explicit engineering suffixes to define hardware builds and communication interface variants. Below is the technical breakdown for the ALR121-S00 configuration:
ALR121: Core base model designator for the dual-port serial communication module.
-S: Standard type construction baseline for standard industrial enclosure installation.
0: Phase indicator slot mapping designator.
0: Basic functionality block revision baseline.
Hardware Specifications
Parameter
Specification
Model
ALR121-S00
Brand
Yokogawa
Origin
Japan
Weight
0.34 kg (Net) / 1.5 kg (Shipping)
Dimensions
Standard CENTUM series I/O slot footprint size
Operating Temp
Standard industrial enclosure environmental parameters apply
Power Consumption
Internally derived via I/O node backplane tracking
Product Type
Serial Communication Modules
Communication Interface
RS-422 / RS-485 (2 ports)
Communication Function
Half-duplex tracking
Synchronization Method
Start-stop synchronization (Asynchronous)
Transmission Code
Binary data structure execution
Industrial Network and Component Architecture
Protocol Conversion Latencies and Throughput The serial communication module establishes a deterministic hardware gateway over its dual RS-422/RS-485 physical channels. By processing incoming binary start-stop synchronization frames directly on its onboard controller, it minimizes protocol conversion latencies when linking external subsystems like PLCs or instrumentation clusters back to the Field Control Unit (FCU).
Intrinsic Safety Barriers and Noise Suppression The differential signaling architecture inherent to the RS-422/RS-485 standard provides robust common-mode noise rejection. This layout suppresses electrical transients and high-frequency industrial interference over long-distance cable runs, protecting the internal backplane logic bus from external ground potential variations.
