Hi all,
I have a question regarding slave adressing on Modbus.
We have a V130 which we want to use as a slave on a Scada system. When I read about slave adressing in the help file the pointer value offset is given for each data type, no problems. However, when I read the examples (and also different topics regarding modbus here on the forum) another offset seem to occur. For example when writing a 3-bit vector of outputs starting at O8:
"SCADA as the Modbus master to color PLC:
Convert the HEX address to DEC. In the SCADA application, set the Slave: Start of Vector parameter to 46393 (30001 + 16384(4000h) + 8) and the Force: Vector Length parameter to 3, enabling the Master device to write to O 8 - O 10 within the slave Vision controller."
Where does the 30001 come from? The 4000h is obvious since it's mentioned in the help file.
A similar offset of 40001 seem to appear when reading/writing MI:s, 400001 for MF:s and so on.
I must be missing something fundamental since I can't find any information about this offset.
A couple of words around this would be much appreciated.
Cheers from Sweden
Anton