The Axia Livewire protocol supports network-based GPIO ports. These can be connected to physical devices (with a DB-15 connector on a GPIO Node), or virtually (such as the Livewire IP Driver). Each GPIO Port has 5 Input Pins and 5 Output Pins. Each pin contains a simple high/low (off/on) status.
To view the current state of these ports and pins on a computer, you can login to the web interface for your GPIO Node (or QOR, or PowerStation) and use the Java plugin. You can also use Telnet – with just two simple commands required! Telnet is particularly handy when you are trying to debug the output of an automation system – the IP Driver doesn’t contain a web interface.
How to View Livewire GPIO Pin States with PuTTY
1. Download PuTTY
PuTTY is a simple Telnet, SSH, and Serial Port client for Windows. If you haven’t already got a copy, go to the downloads page and grab the latest version of putty.exe from under the “Alternative binary files” heading. This will give you a single EXE to run.
2. Run PuTTY
On a computer connected to the same LAN as your Livewire-enabled device, run Putty.exe by double clicking it.
3. Connect to your Livewire Device (port 93)
Every Livewire device runs a simple Telnet/TCP server on Port 93. This is called the Livewire Routing Protocol (LWRP). This is used by Pathfinder to do routing changes, Automation systems to interface with GPIO, and also my handy-dandy LWRP Client. If implemented correctly by the device, it mirrors the Multicast GPIO data that’s also available.
To connect in PuTTY:
- Enter the IP Address of your Livewire device
- Enter Port 93
- Select “Telnet” as the Connection Type
- Press “Open”
3. Enter some simple commands
Once you’ve connected, a black terminal box should appear.
To test you’ve connected properly, press enter a couple of times. The message “ERROR 1000 bad command” should appear. The LWRP likes one command per line, and a blank line happens to be an invalid command – hence, the error.
Now, you’re ready for the real magic! Type the following two lines, pressing enter after each:
After typing each of those commands, the current pin states will appear in the terminal:
Each line in the output represents a single GPIO Port.
GPI is the inputs, and GPO is the outputs.
The number directly after this is the port number.
The five letters represent each of the five pins. The letters “H” and “h” stand for “high” (off). The letters “L” and “l” stand for “low” (on).
Uppercase pin letters indicate the pin is changing. Lowercase letters indicate the pin is solidly on that state.
Every time a change happens on either an input or an output, a new line appears with the latest state. Changes will usually get two entries each (one uppercase to indicate a change is in progress, and a second lowercase to indicate it’s stable again).
That’s it! A simple way to debug the LWRP on any PC!