What does error BFFF005F mean?

[chrisger]

hi there

i got a Keythley 2700 DVM and a 6220 current supply. i measure the voltage of some channels of the DVM and calculate the new value for the current output of the 6220 supply using AUTORANGE = ON. this is done with a rate of 1HZ. all works fine for some hours (for testing purposes we are measuring the voltage on a constant high precision resistor connected to the supply, so the output current is calculated to a constant value and the measured resistance varies less than 0,1 %)

After some hours of absolutely constant conditions and output current the 6220 supply returns the errorcode BFFF005F "No listeners condition is detected (both NRFD and NDAC are deasserted)" when writing the next current value, but just for a single cycle. after that the supply changes the current range to the next higher level, so the variation becomes ~1 % which is much to high.

anyone got an idea what that errorcode BFFF005F "No listeners condition is detected (both NRFD and NDAC are deasserted)" means?

thy & best regards

chris

[Makoto]

The error code 0xBFFF005F means there is no GPIB listener.  It typically happens there is no instrument having the expected GPIB address, or GPIB cable is just disconnected or corrupted.  For example, if you have a VISA session from "GPIB0::7::INSTR" viOpen call, a writing action using viWrite or viPrintf will generate the 0xBFFF005F, if the instrument with GPIB address 7 does not exist, turned OFF, or GPIB cable disconnected.

For your case, as the instrument has been working fine through GPIB for a long time then that error suddenly occurs, the instrument firmware bug or GPIB cable's contact failure are suspected.

[chrisger]

hi makoto

you were right: i contacted the supplier and it seems to be a bug in the device. the cable is ok because sometimes the device shows erroneous behaviour BEFORE the error code occurs.

best regards

chris