weed tech makes some nice interface modules, several of which I already support in XTension. Something I've been meaning to get ahold of is their analog output card so that I might make use of some of these old meters that I've collected. I broke down and bought myself the thing the other day ;) I had to revisit the code anyway to support serial connections over IP/serial adaptors and add support for their new analog input module anyway so I decided to add this to the list of maintenance being performed.
There is still a lot of work to be done before it will be ready for full integration and I've mucked up the queue handling somehow in the process, but as far as a demo of the possibility it works great. More fun coming when it's all cleaned up.