Modbus configuration in CBF2013
I am trying to read the data from a SEL box (Schweitzer Engineering Laboratories).
The SEL box will be the master and the AC900F will be the slave. The starting address from the SEL box will be 400020 to 400020. In another words, the address i am trying to read is from 400020 bit 0 to 400020 bit 15.
In my CBF, i have configured the hardware structure. The IP address for the AC900F is 18.104.22.168 and the IP address for SEL box is 22.214.171.124. I am using FBD, and i have choose MODS_R1C.
What is my start address in the "parameters:Read Coil 1 MODS_R1C" windows supposed to be?
Voted best answer
I suggest using another function, as the data You want to read is hold in a register in memory reserved for holding registers. Use block MODS_R1R. Your documentation doesn't give You address but something called register number. I really don't want to get into details right now but You should use MODS_R1R block with adres 19. If it doesn't work (the values are not what You expect), then try address 20. Then simply UNPACK WORD TO BOOL to read single bit values.
The whole problem with Modbus is that although there is a standard of addressing, it's not followed by some companies, so there is alway much confusion when it comes to finding the right address.
Hope it helps,