ALR121-S53 Yokogawa CENTUM VP Series Datasheet & Technical Manual
Manufacturer: Yokogawa
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Part Number: ALR121-S53
Condition：New with Original Package
Product Type: Serial Communication Modules
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Country of Origin: Japan
Payment:T/T, Western Union
Shipping port: Xiamen
Warranty: 12 months
Yokogawa ALR121-S53 CENTUM VP Module
The Yokogawa ALR121-S53, also cataloged as the ALR121 Serial Communication Module, operates as a dedicated hardware component for serial data transfer within CENTUM VP / CS 3000 networks.
Suffix Breakdown & Model Matrix
- Base Model: ALR121 (Serial Communication Module, 2 ports, RS-422/RS-485 physical layer layout)
- Suffix Type (-S): Standard type execution
- Explosion Protection (5): With no explosion protection circuitry
- Revision Indicator (3): Specific connector configuration and firmware execution layout
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | ALR121-S53 |
| Brand | Yokogawa |
| Origin | Japan |
| Weight | 0.34 kg |
| Dimensions | Standard ER bus slot dimension footprint |
| Operating Temp | -20 to +70 deg C |
| Power Consumption | Current consumption of 0.5 A at internal logic rails |
| Serial Channels | 2 independent hardware ports |
| Physical Layer Interface | RS-422 / RS-485 (4-wire balancing structure) |
| Native Protocols | Modbus slave communication function, subsystem link communication |
| Structural Shielding | Integrated full EMI shield barrier (foil + braid alignment) |
| Isolation Barrier | Galvanic insulation between field wiring terminal blocks and system bus |
| Storage Temperature | -20 to +70 deg C |
| Humidity Resistance | 10% to 90% RH, non-condensing |
4-20 mA HART Loop Protocol and Subsystem Data Linking
The ALR121-S53 manages high-density data synchronization pathways, acting as a critical interface that bridges external device networks to the primary DCS framework. This module works in conjunction with 4-20 mA HART loop protocol architectures by handling digital variable communication flags derived from remote instrument channels. The dual-port design uses independent physical lines to ensure channel-to-channel isolation parameters, which prevents field ground loops from causing error frames in process calculations. Cold junction compensation (CJC) algorithms handle software variables smoothly across the subsystem link, maintaining structural parity with Modbus slave configurations without reducing signal resolution.
Frequently Asked Questions
Q: Can the ALR121-S53 module execute hot-swap maneuvers on an active CENTUM node backplane?
A: Yes, the hardware allows live extraction and insertion within an energized I/O slot. However, physical module swaps instantly terminate active Modbus slave communication loops on both ports, requiring manual data link state clear commands on the master controller to restore operation.
Q: How does the internal controller handle the electrical separation of ports configured for RS-422 vs RS-485 operations?
A: The mode transition is determined via internal register mapping. Each independent hardware port uses dedicated transceivers linked through galvanic insulation planes, guaranteeing that noise spikes on an RS-485 network line do not cross-talk into the adjacent serial data path.
Field Installation Guidelines
- Module Seating and Retention: Slide the card into the designated slot of the CENTUM card cage assembly until the front connector is completely locked. Tighten the integrated retaining screws to ensure solid electrical ground paths.
- Shield Grounding Protocols: Terminate external serial network cables using full EMI shielding connections. The outer metallic braid must secure directly to the grounding bracket of the marshalling panel to ensure low-impedance transient current dissipation.
- Wiring Layout Isolation Constraints: Route all RS-422/RS-485 communication wires away from high-power AC mains, primary power lines, or inductive drive outputs by a minimum of 300 mm to suppress high-frequency induction.
- Terminal Resistance Assignment: For long-distance lines approaching maximum physical distances, install a matching external 120 Ohm carbon-film termination resistor across the RX/TX differential pairs to prevent signal reflection errors.