Yokogawa MAC2*A CENTUM Multipoint Analog Control Card

The Yokogawa MAC2*A, also cataloged as the MAC2 Multipoint Analog Control Card, operates as a dedicated hardware component for multi-loop analog signal conditioning and process variable control within Yokogawa CENTUM DCS platforms.

Suffix Breakdown & Model Matrix

Hardware Specifications

Channel-to-Channel Isolation and DCS Process Loop Control

The MAC2*A analog control card routes multiple independent process control loops across the CENTUM DCS system backplane. Designed with channel-to-channel isolation across signal lines, the module mitigates common-mode electrical noise and prevents ground potential loop currents between field transmitters and control logic. The hardware conditions 4-20 mA HART loop protocol signals and analog process inputs—such as temperature, flow, and pressure variables—translating physical field measurements into synchronized digital values for continuous DCS loop execution.

Frequently Asked Questions

Q: What physical interfaces handle system and field connections on the MAC2*A card?

A: Field signal wiring connects through M4 screw terminals on the mounting nest assembly, while system-level backplane communication is established through the integrated system bus connector.

Q: How does the MAC2*A card suppress electrical noise across adjacent analog control loops?

A: Galvanic channel-to-channel isolation barriers decouple individual control loop circuits, preventing ground potential differentials and cross-channel electrical interference.

Q: What is the input voltage tolerance for powering the MAC2*A module?

A: The card operates from a nominal 24 VDC power supply with an acceptable input voltage fluctuation range of +/-10% (21.6 VDC to 26.4 VDC).

Field Installation Guidelines

1. Card Insertion: Slide the MAC2*A card along the guide rails of the designated CENTUM card nest slot. Seat the backplane bus connector firmly into the backplane socket and secure retaining fasteners.
2. Terminal Termination: Connect field instrument wiring to the M4 screw terminals on the nest terminal block. Tighten terminal screws to standard engineering torque (0.8 to 1.2 N-m) to prevent loose contact under cabinet vibration.
3. Shielding Practices: Ground signal cable shield drain wires at the cabinet functional earth (FE) bus bar at a single termination point. Do not connect shields to both the field device chassis and the DCS terminal block.
4. Supply Voltage Check: Measure the 24 VDC power supply output under load to confirm voltage levels remain within the 21.6 VDC to 26.4 VDC range prior to loop commissioning.