Product Details
Configured for field signal interfacing in legacy DCS architectures, the Yokogawa CA0*A (CAO Interface Module) provides direct physical/electrical execution. It handles signal routing, conditioning, and isolation between field-side instrumentation and system-side backplane communication buses.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | CA0*A (CAO Suffix A) |
| Brand | Yokogawa |
| Origin | Japan |
| Operating Temp | 0 to 55 deg C |
| Power Consumption | Backplane bus powered |
| Primary Voltage | 24 VDC system power |
| Signal Conditioning | Built-in Zero and Span calibration potentiometers |
| Form Factor | Card-edge backplane bus interface card |
4-20 mA HART Loop Protocol and Channel Isolation
The CA0*A module incorporates internal analog signal conditioning networks to stabilize field instrumentation inputs prior to digital quantization across the system backplane. Optimized for 4-20 mA HART loop protocol signaling, the interface board features front-panel Zero and Span calibration controls to correct for field transmitter drift and loop impedance variations. Internal channel-to-channel isolation circuits suppress ground loop voltages and electromagnetic cross-talk, preventing electrical noise from propagating into the central control processor logic.
Frequently Asked Questions
Q: What is the purpose of the front-panel SPAN and ZERO potentiometers on the CA0*A module?
A: The SPAN and ZERO potentiometers allow manual analog calibration adjustments directly on the front panel to compensate for loop impedance offset and sensor drift.
Q: How is operating power supplied to the CA0*A module?
A: Operational power is supplied directly from the host system backplane bus upon inserting the card into the rack assembly.
Q: Does the CA0*A module support hot-swapping during active DCS operation?
A: Online replacement is supported provided standard anti-static procedures are maintained and the module retention latches are disengaged correctly before removal.
Field Installation Guidelines
- ESD Protection: Attach an anti-static wrist strap connected to cabinet frame ground before handling the circuit assembly to prevent static discharge damage.
- Module Insertion: Align the printed circuit board edge with the sub-rack card guides and slide the module smoothly until the backplane edge connector fully seats.
- Calibration Verification: Use a precision current calibrator across test terminals to verify Zero and Span settings after completing physical installation.
- Shield Grounding: Ensure overall cable drain shields are landed onto a single instrument earth bar to prevent circulating ground currents across field loops.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
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- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.





























