From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
Then please do not start a new thread for the same issue. People won't know where to respond. I specifically can't help you with the 5660, but I did find this: Setting RF Attenuation on the NI 5660/5661. If you still have problems you can try to contact NI support directly to try to talk to someone else.