this is a snap shot of the MTU 5000 MTU, I believe the 1000 mtu uses the same chip and the data stream is the same as my software for the RDU works with either the 5000 mtu and the 1000mtu
the red dots signify the trace and the pin that I am capturing data from then MTU micro controller with the esp8266 and the ardiuno . these pins go directly to the power line encoder … TDA5051A modem pin one DATA input
so I think they both use the same modem so you just need to connect to this pin on your older MTU (if using different modem you just need to determine the DATA IN to connect to) and then to RX pin on the ardiuno or esp
AN10903.pdf (446.6 KB)
hope this helps you - the software will work with either MTU just remember to set serial 1200 as that the data rate of this connection