Table of Contents

Arduino IDE · Connecting an HMI with LS Electric Cnet

HMI Connection overview · Arduino IDE setup

In LS Electric Cnet, the HMI sends Cnet serial requests and the product answers as the Slave. In LS Electric, M2I, and EasyView HMI editors, enter M and D memory names such as D000 and M000. In a Cnet request, %DW0 corresponds to the product's D0, and %MX00000 corresponds to M0.

The example on this page uses MPINO-8A4R-S · RS-232 Serial1 · station 1 · 9600 bps · 8N1. Check channels and wiring and SDK installation and board selection. You do not need to complete the Modbus example first.

1. Addresses for the HMI screen

Screen element SDK internal memory HMI entry example Operation
Communication check number D0 D000 16-bit word read, repeats 0~99
Number input D1 D001 16-bit word write, 0~9999
Returned value D2 D002 16-bit word read, same as D1
Test switch and lamp M0 M000 Bit toggle write and read

The HMI entry examples apply to LS Electric, M2I, and EasyView HMIs. For other HMIs, check the address format of the selected Cnet driver. The Modbus address conversion table does not apply to Cnet. Number format, switch, and lamp settings are covered in Building the HMI Screen.

2. Enter the complete code in a new sketch

This simple example exchanges internal memory values through the Cnet variables above. It does not use any real input or relay output pins. 

#include <Arduino.h>
 
unsigned long lastTick = 0;
 
void setup() {
  ICnetMem(16, 16, 0);       // Includes M0 and D0~D2; R area not used
  ICnetAdr(0, 0, 0);         // External addresses also start at 0
  ICnetInit(Serial1, 1, 9600);
  lastTick = millis();
}
 
void loop() {
  if (M == nullptr || D == nullptr) return;
  ICnet();
 
  unsigned long now = millis();
  if (now - lastTick >= 1000UL) {
    lastTick = now;
    D[0] = (D[0] >= 99) ? 0 : D[0] + 1;
  }
 
  if (D[1] > 9999) D[1] = 9999;
  D[2] = D[1];
}

ICnetMem() allocates the memory at startup, and ICnet() handles HMI requests on every loop.

3. Verify, upload, and build the HMI screen

After uploading the sketch, place the HMI elements using the screen example below and the address table above. D0, D1, D2, and M0 in the figure are product memory names. In the HMI editor, enter D000, D001, D002, and M000 from the table.

D0 communication check number, D1 input, D2 returned value, M0 test switch and lamp

  1. Save the sketch and run Verify in Arduino IDE.
  2. Check Tools → Board and the upload COM port, then select Upload. See Getting Started with Arduino IDE.
  3. In Building the HMI Screen, assign D000~D002 and M000 from the table above, then transfer the HMI project.
  4. Turn on the product and the HMI, then test read → write → bit in Checking Operation and Troubleshooting.

The HMI writes D1 and M0, then reads back the product's D2 and M0 to check the result

Confirm that your HMI driver sends Cnet %DW and %MX requests. Expected results and where to look for each symptom are listed in Checking Operation and Troubleshooting.