Does it need a termination character? (probably) Did you send a termination character? (I don't see one in your command.)
Hit enter at the end of version. Or type /n or /r.
I also am not sure which GPIB to choose.
I tried GPIB0 and GPIB4 and GPIB5 then "Scan for Instrument".
What model of oven and/or controller are you trying to talk to? There are plenty of other settings to worry about that might show up in the manual.
That looks like it's supposed to be a query. Did you click the "Query" button? (Alternatively, did you click "Write" followed by "Read"?)
How many ovens do you have connected? I see 10 instruments listed in your NI-MAX list. Are they all powered on? How long are the cables between them? Have you specifically set the address on each oven? What is the address you are attempting to contact? (In your first post its GPIB0::4::INSTR, but its not shown in the list in the latest image.)
GPIB has some restrictions on cable length (2m between instruments/repeaters) and a total of 20m of cable length. Also I think its 2/3 of the instruments have to powered on at any time. If you have a huge long run on cabling, and most of the instruments are off your feeble GPIB querry just gets lost and eventually you get that timeout error.
I would try to send either "Status?\r\n" or "Temp?\r\n".