DNP3 Slave Over CDMA for Small IO Count

I am seeking a DNP IO Slave, to connect to my DNP3 master via CDMA (Verizon, North America). My company manufactures a DNP3 PLC, but it is way overkill for the 6 inputs we need to monitor from an existing system, and we are working with limited space. The control circuit I am monitoring is 240VAC, so 240VAC inputs would be an advantage as it will remove interposing relays.

Thanks for any suggestions!

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And before anyone flames me, yes, I have done my own research; on Google, AB, Avantech and B&B.