Bus Extender

Bus Extender

When an electrical panel is saturated, it can be useful to move a part of the Wago controller a bit further away. For this purpose, it is possible to extend the communication bus between Wago modules using an RJ45 network cable. However, it is important to note that this is not an Ethernet network; connecting the bus directly to an Ethernet switch is not an option.

To create an extension, two specific modules are required:

• Module 750-627: the beginning of the extension. Place this module at the end of the first Wago line, replacing the terminator usually present.

• Module 750-628: the end of the extension, and potentially the beginning of the next one. Place this module at the beginning of the second Wago line, then place the input/output modules, followed by the terminator that you initially had at the end of the chain.

The principle is straightforward. Simply activate the extender option and place the modules; no special programming is required. The maximum cable length between two modules is 5m. The documentation indicates the possibility of extending up to 10m with certain Wago heads, and on forums, it is common to see testimonials of lengths greater than 5m. This is probably due to interference and the stability of the transmitted signal. It is advisable to use good quality cable, such as Category 6, for example. This module has a switch with two positions 0/1, indicating whether it is chained to another bus extender.

• 0: Yes, there is still an RJ45 cable and a 3rd Wago bus,
• 1: No, no other extender. The second RJ45 port is not used.

The 24V power supply is not transmitted through the RJ45 cable, so it must be provided by another cable to power the second part of the Wago.

Enabling the Bus Extender Option

It is necessary to check a box on the free software Wago Extension Setting.

Go to the “Connection” section and enter the IP address of the Wago controller. Ensure beforehand that your PC and the controller can communicate over the network.

The main window displays “Device at X.X.X.X” and “Ready” in the lower part of the window.

Select the “Enable” button to activate the extender option.

That’s it, you’re done.

If not already done, plug in the cable and, if necessary, restart the controller. It should recognize all your input/output modules as before.

Principle Diagram of a 3-chain Wago Installation

Alternative Solution

An alternative method is to only relocate the relays to a secondary panel. For this, a stranded cable (20×0.8, for example) must be pulled so that the relays can be controlled remotely from the Wago.