Ahh...
It seems to me, like you have to send the complete set of characters every time. To set +7V for example, you have to send "V1+07.00000" that seems to work.
I tried a lot of time with the "L" command, because I thought one can't do anything wrong with just one character, but it still doesn't remove the "REM" light.
But that is ok. I can control it via GPIB, now
@0xPIT: Mine has no 1kV option.
Another problem I have is the linearity calibration. It seems to me, like one of the steps cannot be tuned, because the pot is already at the end. Therefore, it seems like I have to replace a resistor. Shouldn't be a great deal, I think.