Hi to everyone,
I got an AB7000-C back-up from a client, asking to add some modbus command for the same slave.
Currently, the module it’s working properly, in fact i’m able to read the valus from my S7 400 (as a master profibus), but there is something i don’t understand.
For all the response arriving from the modbus slave, it’s been reserved an amount of memory bigger than the necessary. for example:
first query:
01-03-1c-e9-00-0f (15 registers, from reg 7401, it means 30 bytes).
first response
byte count 3c (60 bytes)
Register value
Data length 3c (60 bytes)
Data location 00 (from the first byte of the internal memory.
I can assume that, ok the master reads 30 bytes, but stores them into 60, so from 0 to 29 there are my values and from 30 to 59 are empty.
So, why if i try to replace the same configuration at the workshop it doesnt work?
if i try to store 30 bytes into 60 like the original doesn’t work, if i put 30 bytes into the same amount then works.
I dont understand what i’m missing.
Thanks for any advice.
BR.
Peter.