Photon/Electron using TinyGPS and Modbus


I am new to the forum and to the Particle family. We just received an Electron and Photon board to play with and wanted to find out first if we can accomplish the following task with either board.

We are looking at hooking up the board (eventually, we will use the Electron since we need Cellular connectivity) to a Modbus industrial controller where we need to monitor (read modbus 03) 32 channels and report back any change in values, in addition we need to report Lat/Lon and elevation. I managed to successfully use a GPS module in the Photon board using the TinyGPS library available in the WEB IDE and I was just wanted to see if I can use the Modbus Master available but I noticed that I only have one serial interface in the Photon. Doing a quick search on the forum I noticed that serial-software is not an option. Would someone give me some direction as to what options do I have?

Your help is greatly appreciated,