Yokogawa VC401-10 Coupler Module

Supports standard analog output: 4-20mA current signals, 1-5V DC voltage signals, etc., adapting to various actuators.

Can be configured with linear or non-linear output characteristics to meet special process requirements (e.g., non-linear compensation for valve opening).

Output accuracy reaches ±0.05% FS (full scale), with 16-bit digital-to-analog conversion (DAC) to ensure the accuracy of control signals.

Built-in hardware filtering and software calibration functions suppress temperature drift and external interference, ensuring stable long-term operation.

Supports real-time communication with controllers via Yokogawa's internal bus (such as the HW bus) to receive control commands and status feedback.

Equipped with a fault diagnosis interface, enabling real-time monitoring of module status (e.g., output anomalies, open circuit alarms) through system software.

Electrical isolation: Optocoupler or transformer isolation is adopted between the input and output sides, with an isolation voltage ≥500V DC to prevent ground loop interference.

Redundancy function: Supports hardware redundancy configuration (such as dual-module hot standby), enabling automatic switching during faults to ensure uninterrupted system operation.

Protection level: Meets industrial environment requirements, resisting vibration, dust, and electromagnetic interference (EMI).

Output range and fault-safe modes (such as maintaining the current value or outputting a safe value) can be configured online through dedicated software (e.g., Centum CS3000).

Supports hot-swapping, eliminating the need for shutdown during maintenance and improving system availability.

Command acquisition: The module receives digital control commands (such as 16-bit binary data) from the controller via the internal bus (e.g., HW bus). The commands include target output values (such as digital codes corresponding to 4-20mA) and functional parameters (such as range and fault mode).

Data parsing: The built-in microprocessor (MCU) parses digital commands, performs verification (such as CRC check) and format conversion to ensure data accuracy.

D/A conversion: A 16-bit high-precision digital-to-analog converter (DAC) converts digital codes into analog voltage signals (e.g., 0-5V DC), with conversion accuracy guaranteed by a reference voltage source (such as a high-precision voltage reference chip).

Signal conditioning:

Current/voltage conversion: Convert voltage signals to standard current or voltage outputs according to configurations:

Load matching: The output circuit features impedance matching design to avoid signal distortion or module damage due to abnormal loads (such as short circuits or open circuits).

Isolation design: Electrical isolation between the input side (digital signals) and output side (analog signals) is achieved through optocouplers or transformers, cutting off ground loops to prevent external interference (such as frequency converter harmonics) from affecting control signals, while protecting the controller from on-site faults (such as overvoltage).

Multiple protection mechanisms:

Feedback mechanism: The module samples output signals in real time, compares them with target values, triggers self-diagnosis if the deviation exceeds the threshold (such as ±0.1% FS), and sends fault information (such as "output anomaly") to the controller via the bus.

Redundancy function (if configured): In dual-module redundancy, the main module and slave module synchronize data in real time. When the main module fails, the slave module automatically takes over output, with a switching time ≤10ms to ensure control continuity.

Power management: The 24V DC input is converted into voltages required by each chip (such as 5V, 3.3V) through internal DC-DC conversion. Filter capacitors and voltage regulators reduce ripple to ensure stable operation of the DAC and processor.

Clock synchronization: The internal clock provides a timing reference for DAC conversion and data processing, supporting synchronization with the system bus clock to ensure the time consistency of outputs from multiple modules (such as coordinated actions of multiple actuators in complex control systems).