Overview

Once a Modbus map has been fully configured and saved, it can used in remote device addresses (under Settings → Installation). Note that a map doesn't do anything until it's added as a remote device and at least one local register is created to store data based on that map.

The process for this varies based on whether the map applies to a Modbus RTU or Modbus TCP device. Make a note of the map name - it will be required to configure the eGauge.

The steps in this article assume that a Modbus map for the third party hardware has already been created or uploaded to the eGauge. For links to steps for creating or sharing a Modbus map please refer to the Additional Resources listed at the end of this article.

Prerequisites

• This is an advanced configuration topic. Before beginning you should be familiar with basic eGauge configuration.
• Before beginning all hardware should be installed and the correct Modbus map should be on the eGauge meter.
• All remote devices need to be properly configured and wired to communicate by Modbus RTU or TCP.

Instructions

Step 1: Add & define the Remote Device on the Installation Settings page using the method for your communication protocol: 

Modbus RTU

Modbus RTU device addresses are prefixed with modbus:// and end with the address of either a USB port when using the USB-RS485 adapter (USB1 or USB2) or the MAC address of a Serial to Ethernet converter. 

In the example below, the map XY-MD02 is associated with a serial to USB adapter in USB port 1: 

Serial settings can also be added if default serial settings weren't specified in the map or if different serial settings need to be used. For example:

In the above example, the serial settings are:

Finally, it's also possible to specify a different Modbus address/slave address/unit number. This will be necessary if a default value isn't specified or if multiple devices are on the same serial chain. To do this, add the address in the form .X after the map name, where X is the address. For example:

In the above example, an address of 55 is used instead of the default.

Modbus TCP

Modbus TCP devices have no prefix, and end with the IP address or MAC address of the Modbus device on the local network. Note that Modbus TCP devices must be on the same local network as the eGauge.

In the example below, the map XY-MD02 is associated with the address 192.168.1.25 (presumably the same network the eGauge is connected to):

A different Modbus address/slave address/unit number may also need to be specified. To do this, add the address in the form .X after the map name, where X is the address. For example:

In the above example, an address of 55 is used instead of the default.

Step 2:  Create local registers to record Modbus readings.

To create a local register and record data from a remote device, you must first validate the Modbus address. To do this, click the grey "?" to the left of the remote device address. A green check mark should appear. If a red "X" appears, it means the remote device is unreachable or the address or map is configured incorrectly.

Once the green check mark appears, registers can be added to the eGauge configuration to store data fetched from the Modbus device. In the example below, the eGauge is importing two registers ("Humidity" and "Temperature") from the remote device "Sensor":

Step 3: Repeat Step 2 as needed to add registers for additional readings.

Step 4: After adding registers be sure to save changes by clicking Save at the bottom of the page.

Troubleshooting and Tips

• Issue: A red X appears instead of a green check mark when resolving the remote device.
  • Solution: Check the remote hardware for proper wiring and configuration. 

Additional Resources

How to: Create a Custom Modbus Map

How to: Share Custom Modbus Maps