Does this Exist?

I have a customer with and idea and I'm wondering if something like this exists.

He has remote I/O drops throughtout his system and each contains a standard mix of digital and analog inputs. He is maxed out on the digital intpus but has an analog open. He had this idea which goes someting like this.

A "black box" that has inputs for three additional digital inputs. Based on the inputs that are on, generate a unique analog signal. For instance, if the first input is on generate 1 volt, If the second is on, generate 2 volts; if both inputs 1 and 2 are on generate 3 volts... etc.

This could actually work with more than 3 signals but the 3 makes it easily seen what he is trying to do.

I konw I can make up somethnig that will do this w/a brick plc but I thought I'd check first to see if something already exists.

Thanks,

Devicenet maybe?Its digital, but similar in application.

The concept is very simple and exists, known as a digital to analog converter or D/A. I don't ever remember actually seeing an off the shelf device made for the exact purpose you are referring to (e.g 24VDC voltage inputs with 0-10V output). If you know a little about electronics, you could fairly easily build a custom circuit with an OP amp and a few resistors.

You could do this with a GE Fanuc Nano PLC.
http://globalcare.gefanuc.com/search/glbCareProdManuals.asp
Search for GFK-1645