Rs485

I am trying to talk to a Spectrum Controls SOI 200-AB that has a RS485 using a PC serial port. Any clues or knowledge will greatly be appreciated.
thanks for any help
reed

User Manual link: http://www.spectrumcontrols.com/pdfs/soi/SOI-260_guide.pdf

It looks like you can use DIP switches to set up the communication ports in RS-232 mode, which would make it straightforward to connect to your PC's RS-232 port.

If you want to talk to it in RS485 mode, you're going to need a compatible converter. I like B&B electronics units, but have no experience with using them with this old HMI device.

This type Spectrum only has RS485 port (no RS232). Therefore I must use RS232 serial port on PC to talk to RS485 on Spectrum
reed

What about this:

http://www.automationdirect.com/adc...rial/Serial_Isolators_-a-_Converters/USB-485M

It is USB, but maps to a virtual com port.