Modbus TCP/IP – Support

The first step in Cloud Logging is setting up a data source. This is done by selecting a communication protocol and defining the variables. This article shows you how to do this for communication via Modbus TCP/IP.

Select a communication protocol
Add variables (new, import)
Test variables
Manage variables (export, duplicate, remove)

Select a communication protocol

You first have to select a communication protocol. This is the protocol that the x500 IoT gateway will use to communicate with the PLC.

Go to [Devices] in the main menu, select the concerning device, open its [Services] tab, and press [Add service].

Name the PLC, enter the PLC’s IP address, and press [Next].

Select your service type: [Data source].

Select the communication protocol “Modbus“. The port number, slave number, and byte order will automatically be filled based on the selected protocol (port 502, slave 1 and byte order CDAB). You can manually edit these if needed. Press [Add].

Available datatypes

X4 Remote supports the following datatypes when using the Modbus protocol:

BOOLEAN
INT8 / INT16 / INT32
UINT8 / UINT16 / UINT32
FLOAT32 / FLOAT64

Add variables

Once you’ve added a Data Source and selected a communication protocol, you can start adding variables. This is done in the configurator tool, specifically designed to quickly add, duplicate, import, export, and remove variables.

Go to [Devices] in the main menu, select the concerning device, open its [Services] tab, and edit the target’s services.

Select [Data source] and press [Open configurator].

To add a variable press [Add variable].

Tip!

It is advisable to add variables in small batches and test the variables periodically to verify the entries.

You can choose to:

Manually add new variables
Import variables from a file (or device)

Manually add new variables

Modbus explained – number vs address

A Modbus number translates to a function code with an address, and vice versa. Depending on your program you will know one of the two notations. Use the following example table for help with translating between the two.

“Number” notation	“Address” notation
Number	Function code	Address
000011	1 – Coil	10
100381	2 – Discrete input	380
400093	3 – Holding register	92
300135	4 – Input register	134

Enter the variable’s name, type, full address, additional information, and press [Add]. The image below contains explanatory text for each text field.

Duplicate

You can easily duplicate this variable if you’re adding variables that are only slightly different. This way you’ll only have to make small adjustments.

Temporary disconnect

After this next step, the config push, the device will temporarily disconnect to reconfigure its settings and will automatically reconnect. This may take a minute.

Finally, press [Push changes] in the config tab to complete the setup.

Next step

Now that you’ve added the variables, you can test if they’re configured properly.

Import variables from a file (or device)

You can easily and effortlessly copy variables from one device to another by exporting the concerning variables (view the “Manage variables” part of this article) and then importing them in your new device. Alternatively, you can manually prepare your variables in the required CSV format to load them all at once into your configurator. The CSV file structure is explained in our “Import variables: CSV file structure“-article.

When you press [Import from CSV-file], you’ll see a browse window.

Select a CSV file to import and press [Open].
When the file has been read, press [Add] to add all variables to your data source.

Temporary disconnect

After this next step, the config push, the device will temporarily disconnect to reconfigure its settings and will automatically reconnect. This may take a minute.

Finally, press [Push changes] in the config tab to complete the setup.

Next step

Now that you’ve added the variables, you can test if they’re configured properly.

Test variables

The test utility is used to check if all the added variables are set correctly. It shows the status of every variable and displays the variables’ latest values if everything is configured correctly. If not, it’ll show an error message.

In the configurator press [Run test].

A connection will now be set up to stream the data directly to your computer, using:

Port	Transport protocol	Application protocol
443	TCP	WebSocket

When the connection is set up and all variables are set correctly, it should look like this:

Unexpected result?

If the test utility shows unexpected values, please check if the addresses and data types of all variables are entered correctly.
If you get no data at all, please also check that the above listed port and protocols are not being blocked by your computer’s or company’s firewall.
TIP: You can use (free) software like Modbus Poll or Modpoll to test your PLC and verify your configuration.

Next step

Now that you’ve tested the variables, you can view our “Configure data tags” guide to start logging.

Manage variables

You can view all defined variables in a list view or table view. Multiple variables can be selected by pressing the icon on the left, or you can select all by pressing […]. These can then be removed, duplicated, or exported to a CSV file.