Introduction

Use the Modbus explicit messaging window to send an explicit message from Control Expert to the M580 CPU.

You can use explicit messaging to perform many different services. Not every Modbus TCP device supports every service.

Accessing the Page

Before you can perform explicit messaging, connect the DTM for the M580 CPU to the CPU itself:

Step

Action

1

Open the DTM Browser in Control Expert (Tools > DTM Browser).

2

Select the M580 DTM in the DTM Browser.

3

Right-click the M580 DTM.

4

Scroll to the EtherNet/IP explicit messaging page (Device menu > Additional functions > Modbus Explicit Message).

Configuring Settings

Configure the explicit message using these settings on the Modbus Explicit Messaging page:

Field

Setting

Address

IP Address: The IP address of the target device that is used to identify the target of the explicit message.

Start Address: This setting is a component of the addressing path.

Quantity: This setting is a component of the addressing path.

Read Device Id Code: This read-only code represents the service that the explicit message is intended to perform.

Object Id: This read-only identifier specifies the object that the explicit message is intended to access.

Unit Id: This integer represents the device or module that is the target of the connection:

  • 255: (default): Use this value to access the M580 CPU itself.

  • 0 ... 254: Use these values to identify the device number of the target device behind a Modbus TCP to Modbus gateway.

Service

Number: This integer (0 ... 255) represents the service to be performed by the explicit message.

Name: Select the integer (0 ... 255) that represents the service that the explicit message is intended to perform.

Data

Data(hex): This value represents the data to be sent to the target device for services that send data.

Response

The Response area displays any data sent to the configuration tool by the target device in hexadecimal format.

Status

The Status area displays messages indicating whether or not the explicit message has succeeded.

Button

Send to Device: After your explicit message is configured, click Send to Device.

Click the Close button to save the changes and close the window.