how i can know the data at Address vb2 was send to the slave?

NamHo

Hi friends !
I am trying to connect a PC (with master function) and 2 PLCs S7-200 (with slave function) by Modbus protocol .
Now,I don't know what would I do ? Can you answer my wonders ?
First, The hardware ? Do i have to use a modem to connect S7-200 to suitable with Modbus protocol or just use cable. How can i connect S7-200 with PC to use Modbus protocol ?
[schnippschnapp]
Please help me soon ! Thanks a lot !
ps: My English not good ! thanks !

Robster

Dear NamHo,

firstly I would recommend you to have a look to these FAQ's. I think many of your questions are answered there:

First: Hardware:
How do you implement MODBUS communication with S7-200?
[schnippschnapp]
regards