How to Connect Remote I/O to a PLC over Modbus

Scan the Network for the iR-ETN

Open Remote IO → Go to the Online tab → Click Automatic Scan to detect the iR-ETN coupler on the network.

Confirm the PC Is on the Same Subnet

Verify that your PC is on the same subnet as the iR-ETN before you continue. The default iR-ETN IP address is 192.168.0.212.

The PC and iR-ETN must be on the same subnet for Automatic Scan to work correctly.

Select the iR-ETN Coupler

In the Automatic Scan window → Select the iR-ETN you want to configure → Click OK.

Review the Detected Modules

Confirm that Remote IO displays the iR-ETN and the connected module information in the project window.

Change the iR-ETN IP Address

Go to Edit → Select Change IP → Enter the new IP address for the iR-ETN → Click OK.

Confirm the New IP Settings

Review the Change IP dialog and confirm the new network settings before applying them.

Edit iR-ETN Parameters

In the Project Window → Select the iR-ETN → Open the Parameter tab in the right column → Enter the new values in the Project Value column while reviewing the current values in the Online Value column.

Upload the Existing Device Data

Click Upload to read the current data from the iR-ETN coupler and display it in Remote IO.

Download the New Configuration

Click Download to write the updated data from Remote IO to the iR-ETN coupler.

Create a New MapleLogic Project

Open MapleLogic → Create a new project → Select PLC-ES as the CPU type.

Add a New Program

In the project tree → Right-click Program → Select New Program.

Create a Modbus TCP Master Program

Under Communication Configuration → Select MODBUS/TCP Master → Enter a program name → Assign an ID number → Click OK.

Add the iR-ETN Slave Device

In the Special Function window → Click New → Enter the iR-ETN IP address → Click OK → Set the slot number to Slot1 → Click Save.

Slot1 is the slot used for the MOD-SENT01 Ethernet module in this example.

Create a Data Block for Analog Input Reading

Click Add → Select function 03 Read Holding Registers (4x) → Enter a Start Address of 2 → Click OK → Click Save.

This step creates the data block used to read the analog input channel on the slave device.

Configure the Modbus TCP Master IP Address

Go to Parameter → Open the Ethernet tab → Enter the Modbus Master IP address → Click OK.

Open the Ethernet Module Settings

Connect and download the project to the Maple Modular PLC → Under Card Properties → Double-click the MOD-SENT01 card to open the Setup Ethernet Module window.

Configure the MOD-SENT01 Ethernet Module

Set Slot to Slot1 → Verify that the IP address matches the Modbus TCP Master device → Set the MODBUS Unit ID to 1 → Click Write → Click Close.

Confirm Both Devices Are Communicating

Before starting this section → Verify that the project has been created and downloaded to both the Maple Systems iR-ETN coupler and the Maple Systems Modular PLC → Confirm that both devices are communicating.

Create a New Scan Program

In MapleLogic → Right-click Program → Select New Program → Choose Scan under the LD Program column → Enter a program name and ID.

Add a Data Block for Coil Control

In the Special Function program → Click Add → Select function 05 Force Single Coil (0x) → Enter a Start Address of 1 → Point the PLC Device value to Y0004 → Click OK → Click Save.

Insert a New Ladder Row

Right-click on R.1 and insert a row above.

Add a Greater-Than Instruction

Double-click the first rung block → Enter the greater-than instruction symbol (>) → Configure the instruction so S1 is compared to S2.

Set the Comparison Values

Set S1 to register D00 → Set S2 to a constant value of 5000 → Click OK.

Add the Output Coil

On the last rung block → Create a coil that points to register address Y04.

Test the Output Behavior

Run the program and verify that the first output on the iR-ETN DM16-N module turns on when the AI04-VI analog Channel 1 value rises above 5000. In this example, the signal generator supplies 6.270 mA.