How to get older value from the buffer if there is an error in read buffer?

[madara77]

Hi.I am trying to do serial communication with a device where i have to send command to get data. But for some procedures the data from the machine freezes. The value does not vary till that procedure is over. When I tried to send command at this time i will get error at VISA read buffer . Is there a way to get previously stored data from the buffer when an error occurs at the read buffer?

Thank you. 

[RTSLVU]

Don't update your table value until you are sure you received good data.

[RTSLVU]

Or how about something like this?

(see attached)