My proposal for the Connectivity section (please proof read it and correct it when I fail to write correct english!):


There are basically two way to connect your mount to your computer (PC or Raspberry PI/Stellar Mate): direct serial cable or Network. In either case you are directly connecting to the motor controller of the mount, the driver does not utilize the services of the Synscan Handcontroller or Synscan app.

1. Cable Connection
You are connecting the serial potr of the mount (motor controller board) to your computer, this is usually done through a USB port on the computer. The motor controller on the mount has TTL level serial connection (0V and 5V, this is very much different from the standard serial port levels, +/-9V which can be found on some older hand controllers!), so you need a Serial TTL-to-USB cable, also known as EQ Direct USB cable (see EQDIRECT interface). Many vendors sell USB to RJ45/DB9 EQDirect-compatible cables and adapters. You connect the USB to your computer or embedded device running INDI and then use the driver to control the mount.
The EQMod driver can also be used with the Synscan controller if PC Direct Mode is enabled in the handset. However, this approach can be problematic and generally not recommended (please be careful here, as the handcontroller's serial port uses RS232 levels, which is different from the TTL levels of the motor controller. Also the pinout of the RJ12 connector on the handcontroller is different!). For wired connections, using EQDirect cable is recommeneded.

Once the EQDirect cable is connected to your computer, it wil be recognised by the linux kernel as a USB Serial device, and a device file is created for it in the /dev directory. You can check that with the "ls -l /dev/ttyUSB*" command. If more than one USB-serail cable is connected (for example one for the external shooter relase of your DSLR) than you will see more than one such file (/dev/ttyUSB0, /dev/ttyUSB1, etc...), you will need to identify which one is which. They are by default numbered in the order they connected or in the order the linux kernel enumerated them.
That device file name must be written in the "Ports" field on the "Connection" tab.

You may also try connecting your USB cable and allowing the system to scan for candidate ports. USB port detection is effective on a number of operating systems.

The BAUD rate is the data rate and must be set to the baud rate of your mount (please refer to the documentation of your mount), most of the SkyWatcher devices operate at 9600 baud. Changing this number will result in a failure to comnunicate unless at some point SkyWatcher changes the firmware settings in their hardware.

2. Network connection

It is OK as it is, but I would put a screenshot showing, as this is the most common case. I would also link to the Az GTi documentation as there are very nice diagrams detailing the different cases (100% applies to our case).