How to use VISA to control a RS-485 interface.

[Ben]

Hi All,

I am devloping an app that needs to talk to a custom made device using full-duplex rs-485. There are two types of operations I have to accomplish.

1) Down load micro-code and stuff like that when ever a user pushes a button.

2) Deterministically transmit a small command packet that sets some control parameters.

I will never have to do both operations at the same time.

I would like to do task 1) in a windows environment.
I have to do task 2) using LV-Real Time.

The windows machine will be in full control of the RT system, so I will be able to dictate that the two operations never happen at the same time.

So...
A) Is this hardware config "legal"?

B) Is ther any thing special I have to do
(like got into tri-state mode)?

C) Does any one have examples or hints that would help me get through this project with a minimum of blood loss?

Thanks for reading this,

Ben

[Chad_H]

Ben,

See these documents:

KnowledgeBase 17M6L0TI: What Are the Different Transceiver Modes on the NI RS-485 Serial Cards?

KnowledgeBase 2EMAARXY: How Can I Configure My Serial Board for 2- or 4-Wire Mode in LabVIEW RT?

Regards,

Chad H.
Applications Engineering
National Instruments
http://www.ni.com/ask