You can download the latest firmware from http://www.brainboxes.com/software
Simply click on the section named "Latest Firmware" under "ES" so that you get the firmware made specifically for your ES-020.
Once downloaded you run a scan for new devices and then connect to the ES-020.
If you're struggling to find the device, try rebooting the ES-020 and make sure that your computer is set up to automatically obtain IP address. You can also have issues after changing to Static IP for the first time. Try rebooting the ES-020 and give your computer a restart, this more often than not helps you to find your device again in Boost.IO.
When you have managed to connect to the ES-020 via Boost.IO, enter your preferred browser and enter the IP address of the Brainbox ES-020, from here navigate to the Protocol Tab located to the left, then change your Current Protocol settings to Modbus TCP. This needs to be done because by default your Brainbox Device will come from the factory with ASCII protocol.
Once you have connected to the Boost.IO application and changed the protocol on the ES-020 you are free to play around with NodeRED and the Modbus strings.
Hope this helps.