Messung 4310 Analog Input

The Messung 4310 is a specialized Analog Input/Output Expansion Module designed for the Nexgen 4000 series (and sometimes the XMP8 series) PLCs. Messung, an Indian automation pioneer (now largely integrated with Mitsubishi Electric), developed this module to handle high-precision analog signals for process control.

The 4310 is a “mixed” module, meaning it provides both input and output channels in a single block, saving space on the PLC backplane.

1. Channel Configuration

The 4310 is typically configured to handle a mix of standard industrial signals:

• Analog Inputs: 4 Channels.

• Analog Outputs: 2 Channels.

• Signal Types: It is designed to interface with 4–20mA current loops or 0–10V DC voltage signals, which are standard for sensors (pressure, flow, level) and actuators (VFD speed references, proportional valves).

2. Technical Specifications

3. Wiring and Terminal Layout

The module features a front-facing terminal block. Wiring accuracy is critical because the module uses the same terminals for different signal types depending on the jumper settings or software configuration.

• Shielding: It is highly recommended to use twisted-pair shielded cables for all analog connections to prevent EMI (Electromagnetic Interference) from nearby motor power cables.

• Grounding: The shield should be grounded at only one end (usually the PLC end) to avoid ground loops.

4. Integration with Nexgen 4000

To use the 4310, you must configure it within the Messung programming software (typically DOST or NexgenIE):

1. Slot Assignment: You must specify which slot the module occupies on the base rack.

2. Addressing: The analog values are moved into Data Registers (e.g., D-registers or V-registers).

3. Scaling: Since the PLC sees a raw value (0 to 4095), you must write a small piece of ladder logic to scale this into engineering units (e.g., 0–100 Bar or 0–50 Hz).

5. Key Features

• Status LEDs: The module usually has a “Power” and “Run” LED, and sometimes a “Fault” indicator to show if an input signal is out of range (broken wire detection for 4–20mA).

• Hot-Swappability: Generally, these modules should only be removed or inserted when the PLC rack is powered off to avoid damaging the backplane bus.

Common Troubleshooting

• Erratic Readings: If the values jump around, check for common-mode voltage issues. Ensure the 0V of your sensor power supply is referenced correctly.

• Zero Reading: If a 4–20mA sensor shows “0” instead of “819” (the 4mA equivalent in 12-bit), there is likely a break in the loop or the sensor is not getting power.