Unable to change transceiver mode (4 wire to 2 wire) for USB 485 serial port

[ah.bic]

I am trying to setup a USB-RS485 device as per this knowledge base document:

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019MPySAM&l=en-US

However all of the Advanced options under the serial com port are grayed out and changing the transceiver mode from 4 wire to 2 wire is not possible. How can I enable these?

Thanks.

[Andy-C]

Hi ah.bic,

Are you using a serial card or your machine's built in serial ports? Have you confirmed that these ports are configured correctly (IDN command, loopback test, etc)? Finally, what version of the NI-Serial drivers are you currently using? You should update to the latest NI-Serial drivers if you haven't already.

I hope this helps!  

Andy C.

Applications Engineering

National Instruments 

[JasonSmith · Accepted solution]

On Windows Vista and later, these settings can only be modified by running MAX as Administrator. Just right-click on the icon, and choose "Run as Administrator", and everything should be available to you.

[ah.bic]

Andy, Jason,

The device is a National Instruments USB to RS485/422 interface cable (https://www.ni.com/en-us/shop/model/usb-485.html). Jason's solution of running NI MAX as admin provided access to the settings.

Many thanks.

Al