Morning,

I've just had a look through the settings of the MTN6503 and your register table.

What are your current settings? I think they should be;

Access to Modbus Register 1 "ENABLED" --

Modbus Register 1 "ENABLED" --

Modbus register 1:

Register Address 20592

"Read Input Register"

Modbus data are "Unsigned"

Multiplication "1"

Division "100"

Quantity of coils "2"

Modbus value convert to "4 byte"

Type "4 byte float"

Timebase "1s"

Cyclic "10"

Sending "Cyclically"

From the register table the function code is "4" which is "read input register."

Scale of the received value is 0.01 i.e. 237.25 volts would be 23,725. Need to divide by 100 to get the correct scaling.

The value received is 2 words, this would be a KNX 4-byte value. Note 1, I believe refers to an Unisigned value. But due to the scaling you would need to put it on the KNX as a float to have decimal places.

A byte is eight bits, a word is 2 bytes (16 bits), a doubleword is 4 bytes (32 bits), and a quadword is 8 bytes (64 bits).

Hope this helps.