How To Map Mitsubishi Analog Inputs on Weintek HMI?

This article explains the process of displaying analog input data from the PLC to the Weintek MT6071iE HMI via RS232 serial communication. In this system, an analog voltage signal ranging from 0 to 10V (adjusted using a potentiometer) is read through the PLC’s analog input port. The data is then processed using the RD3A instruction to convert it into a 12-bit digital value (ranging from 0 to 4095). The resulting data is displayed on the HMI by accessing the appropriate word memory address in the PLC.

Contents

Required Devices

How To Map Mitsubishi Analog Inputs on Weintek HMI — Wiring Diagram

1. FX3U-14MT Lollette PLC

This PLC is a compact unit based on the Mitsubishi FX3U series and manufactured as a compatible version by Lollette. It is equipped with 8 digital inputs, 6 transistor outputs (sink type), 4 analog inputs (0–10 V), and 2 analog outputs. The device operates on a 24 VDC power supply and features an RS-232 DB9 serial communication port with a default baud rate of 38.4 kbps. It is suitable for prototyping, simulation, or small-scale automation learning. However, since it is not an official Mitsubishi product, it is not recommended for certified industrial control systems or environments that require high reliability.

2. EasyBuilder Pro Software

EasyBuilder Pro is a software developed by Weintek for designing graphical interfaces on HMI devices, such as indicators, buttons, charts, and alarms. In addition to interface design, the software is used to configure HMI communication settings with PLCs, including protocol type, baud rate, parity, and register addresses. EasyBuilder Pro supports a wide range of communication protocols, including Mitsubishi FX series over RS232 and RS485.

3. Weintek MT6071iE HMI

This HMI is a 7-inch touchscreen device with a resolution of 800×480 pixels. It supports serial communication through RS-232 (COM1) and RS-485 (COM2 & COM3) ports, along with USB connections (mini USB and USB host). The device can be used to read from and write to various PLC types, including Mitsubishi FX3U. It also supports program transfer via USB or Ethernet (if available).

4. GX Works2 Software

GX Works2 is the official software from Mitsubishi Electric used for programming, configuring, and monitoring MELSEC series PLCs such as FX3U and FX5U. It supports a wide range of instructions, including basic logic (LD, OUT), analog functions (like RD3A), and serial communication. The software also provides offline simulation and online monitoring functions for real-time system diagnostics.

5. DB9 RS-232 Male to Female Cable

This cable is used for serial communication between the PLC and HMI. The male end (pin) connects to the RS-232 port on the FX3U-14MT PLC, while the female end (socket) connects to COM1 (RS-232) on the Weintek HMI. The cable length should not exceed 15 meters to maintain stable signal quality and avoid electrical noise interference.

How To Map Mitsubishi Analog Inputs?

In the video below, we tested the potentiometer as analog input in PLC and shown the respective analog values on the HMI using RS232.

Initial Preparation

1. Power Supply Setup

Connect a 24 V DC external power source to the FX3U-14MT PLC.

2. PLC-to-PC Communication

Connect the PLC to a computer using an RS232 to USB serial cable. Ensure the cable is compatible with the DB9 serial port on the PLC.

Analog Input Configuration on FX3U-14MT PLC

1. Programming with GX Works2

Create a program in GX Works2 using the RD3A instruction to read analog input values from the PLC’s input channels.

Module Configuration: Use parameter 0/K0 to reference the internal analog module.
Analog Input Channel: Specify the input channel to be read, for example, 1/K1.
Data Storage Address: The analog reading will be stored in word memory (D100) ANALOG INPUT DATA.
Instruction Trigger: Use a Normally Open (NO) contact from system bit M8011 as the trigger condition for executing RD3A. The M8011 bit turns ON automatically every 250 ms, making it suitable for periodic reading.

Weintek HMI Setup to Read Analog Input from PLC

2. Device Connection Verification

Ensure the USB to RS-232 converter is connected and recognized by the operating system.

Open Device Manager on your computer and identify the active COM port (e.g., COM5).

Confirm that the serial communication parameters are set as follows:

Baud Rate: 38400 bps
Data Bits: 7
Parity: Even
Stop Bit: 1

3. Communication Settings in GX Works2

Configure the communication interface in the software to connect with the PLC:

Go to Connection Detection → select Connection1

Set the following parameters:

Interface: Serial USB (RS-232C)
COM Port: Match the detected port (e.g., COM5)
Transmission Speed: 38.4 Kbps
Data Bits / Parity / Stop Bits: 7 / Even / 1

Run the Connection Test and ensure the message “Successfully Connected with the FX3U/FX3UC CPU” appears.

4. Program Transfer to PLC

Once the connection is verified:

Navigate to Online → Write to PLC
Select Parameter + Program to upload all the configuration and logic
Click Execute to transfer the program to the PLC memory. Wait for the process to complete without errors.