I have a Allen bradley plc-5/40c & and one operator station with wonderware Intouch as monitoring software. what is the best way to connect this pc to plc? which hardware i must provide for communication?
Cheapest way is serial using an RS232 cable and the DF1 driver in Intouch, if you have the IO server license. The other option is to use a DH+ connection which will need a PKTx card for PCI slots on the PC, and is a bit pricey but you can still use a WWare IO server. Then there are a couple of other options like setting up a ControlLogix gateway, or the USB to DH+ which will need RSLinx. If the PLC5/40 is Ethernet then you could use this, not sure if WWare has an IO server to suit.