Pci-485/4

[Moshe]

I have a.Pci-485/4 card under WIN-98.I wrote an API for serial comm with CVI. I am using a.loop back for testing my communications, The RS-232 (On board COM) works properly, and the RS485 does not work (I send a.string and receive an empty string), My quations are:
1. Why the Api works properly with rs232 and not with 485. (I am using the 10 pin conector Tx connected to Rx).
2. Is it a.software problem (need to use/add a.different api) or a. hardware problem (cable connections).
3. When i am using a.Full Fuplex or Half-Duplex Communication, Do i need to change the api or it is only a.quation of hardware.

Thanks,

Moshe.

[Ben]

First rule out your hardware.

The 485 port should be available to hyperterminal. Get it working there before moving on.

If you have acces to a scope you should be able to see the data on the lines by doing a differentail measurement between the TX+ and TX-.

The board has to be told what mode it is opeartion in. These defaults can be set in the system hardware config.

Ben