I also have a NX-8E panel but I use the NX-586E module to connect to openhab. It’s basically a virtual keypad and it’s fairly cheap. My panel already had a serial port for home automation but it spits out what looks like random characters that you have to interpret to figure out what it’s saying. You also have to format commands to the panel a certain way. The NX-586E spits out status to a “coded” string also but it’s 1001% easier to decipher. It’s so easy and reliable i’m not sure a dedicated binding is required. Especially when the binding requires rules to function (looks like the binding in the last link posted uses rules).
What I did (and my suggestion), I basically created a software controller for the panel. I have a pre-existing VM infrastructure so I made my controller virtual but a raspberry pi would be perfect for this use and you can likely power it with the panel. I’m using openhab to connect to the NX-586E and map the output to MQTT topics. This OH instance consist of the serial, mqtt, ntp, mysql binding for persistence, one items file, and one rules file so it’s very simple and light weight. So I’ve basically turned the panel into a network device by mapping REST and MQTT to the various functions of the NX-586E.
Why use a separate OH instance? Because it’s a security device!! By using a dedicated instance for this interface I was able to lock this device down pretty tight. For example you need a cert to SSH to the centos operating system, my switch features port security which is enabled for this server, and i’m able to easily log EVERYTHING this server does for what is essentially forever because i’m not rotating them at all and I have to plans to. If all that wasn’t enough, the server is on a dedicated Vlan and the routes are basically deny everything, in or out, except for my MQTT server. When I need to log into the server (which is highly rear) I enable a rule on my firewall to let my laptop through to port 22, 21, 443, and MQTT(mqtt port is slipping me right now). I also used this method to limit the commands I can send to the panel. The only MQTT topics the panel is subscribe to is for the arm and stay buttons. Maybe one day i’ll open up full 2-way communication but at this point there is zero need for openhab to disarm or bypass zones on my panel. What all of this does is from the outside(outside the environment of the panel not necessarily my house) if i were compromised someone can’t sit there and randomly guess at the pin(s) until it disarms. Just keep in mind that if you’re going to integrate your panel (maybe any panel), since there is no bruit force security on the panel(at least not that i’m aware of) it would be relatively easy for someone write a program to cycle through all 6 digits to guess at a pin, and if you’re only using 4 digit pins… good lord! If you’ve integrated your door locks to the panel and since your IP address can be relatively easily traced to a physical address, it makes the threat a little more real.