anyone tell me that if i bay one plc software from one vendor is it possible to access other vendor plc by any change in software or install driver or change plc cable and how many plc can access.
You didnt specify that you want to access same PLC to other vendor if this is from the same company i mean from the same plateform you can easily access the same. and one improtant thing if the programmer had not put any software lock.
No, if you have for instance software for an Allen-Bradley Control Logix PLC you cannot also program a Modicon PLC. You will need to get software specifically for that brand (and model) of PLC.
PLCs do have drivers and modules that allow them to "talk" to each other.
