Hi, I had been trying to read and write to a port using the .Net 3.5 example codes that are supplied with the controller. Examples\DotNet 3.5\Digital\Generate Values\Write Dig Channel and Read Dig Channel. Regardless of what value I write I always get positive output read and all the bits are high on thge channel. To reporoduce the issue simply run both programs at the sametime Write Dig Channel and Read Dig Channel. Set the port to Dev1/Port0/line0:7 in both tests and write a value that is negative to one or all the channels. When you read the values, the values are all positive. I have tested using the example code in VB and I am getting the same results. Please note that the controller is working correctly when I run the measurement and automation test. I have looked at the Forums and I found the post at: http://forums.ni.com/t5/Measurement-Studio-for-VC/Basic-questions-about-PCI-DIO-96/m-p/242296 The article name is Basic questions about PCI-DIO-96 and it states that the values written should persist. Any ideas on what I can be doing wrong? Thanks, Magued

Here is a LabVIEW and a VB example that demonstrate using tristate to switch between output and input. The Output setting will allow you to drive the liine and read back what you wrote. The read setting will allow you to read an external digital signal. Please excuse the fact that these are both rough and unofficial examples.

Digital I/O

Reading and Writing to a port

Solved!

Author

Hi Beil,

Thanks to you and Frank for your excellent support.

Magued

Message 11 of 11

(716 Views)

Digital I/O

Reading and Writing to a port

Re: Reading and Writing to a port