RS485 - Modbus

I am trying to get values form a range of sensors onto a windows PC. The sensors communicate via modbus using rs485.

I have found activex controls which I can use with VB to communicate via the serial port of the PC, however would this be rs232 or will this also work for rs485?

http://mbserver.tripod.com/ is a free one and there are other commercial item I am looking at.

Does the serial port of a PC only work in RS232 or with these activex controls will it be able to communicate via rs485?

Thankyou in advance for your help. if you require any more information please say and I will try and provide what I can.

cheers

Ben

You have to buy a RS485-RS232 converter to interface a PC to a RS485 Network.

Thanks... I was starting to think that that was the option

Thanks for your quick reply

Ben

You can also buy RS485 cards for your PC (PCI slot). I use one from National Instruments. A little pricey but works flawlessly. Converters can be tricky some times...

Rs-485

The DeviceMaster RTS product offers a remote serial port across an Ethernet connection, and it's reasonably prices. With the driver installed, it is seen as a COM port on the PC, and can be configured as RS-232/422/485 via software.

Contact me for additional details if interested.

You can talk me a exam connect PLCS7-200 to PC using WinCC? Thanks