Holman Engineering railway clocks

This article concerns NSW railway clocks made by: Holman Engineering.

There are two models of these clocks. The first is a single-board computer with a network cable, and the other is a much simpler device which uses RS-422 and has some sort of serial device to program it. The former requires an NTP server at a particular address. The latter requires a serial adapter and currently I haven't figured out how to get it working. I came into these from someone who couldn't get them working, and from the outside they are rather unfathomable beasts.

To get the network version up and running you'll have to first off find a 12v DC power supply. An old computer power supply will work well, and the wattage requirements are low. From here it will start at midnight at powerup after showing a few snippets of information which include the software build date and statically assigned IPv4 address. A very easy way to bypass the need for a network time server and having to plug it into a network is to connect it to a smart power switch and use its inbuilt scheduler to switch on right at midnight and off maybe at 11pm so that there's no persistence.

To find which address it's looking for in order to get an NTP server you may have to use Wireshark, as I imagine different clocks have different addresses that they look for. On top of this you'll probably need an RPi with a static address and a properly-configured NTP server. Unfortunately I don't know if these clocks have the ability to have their parameters modified in some way