Hi,
I'm having trouble getting a 6674A PSU to signal an OCP fault in less than 20 seconds when monitoring faults via the Questionable Status register. I've enabled over-current protection, and set the right bits to have a protection condition trip the PSU on an Over-Current fault, but the PSU will wait 20 seconds before it bothers to set the OCP bit in the Questionable Status register. I had assumed this was down to the OUTPUT:PROTECTION:DELAY being set to a default value of 20, but after changing it to a lesser value (0, 1, 2, etc.) and confirming that it was set to the new value, the PSU still waits 20 seconds before setting the Questionable status accordingly. The indication of the OCP is indicated instantly in the CURR:PROT:STAT? value, but I'd set my software to read all Protection faults via the STAT:QUES:EVEN? query, and would rather not bodge in a fix for one of the flags....
Is there something else that needs to be done to make the PSU use the new value, or am I setting the wrong values all together?
Thanks
I'm having trouble getting a 6674A PSU to signal an OCP fault in less than 20 seconds when monitoring faults via the Questionable Status register. I've enabled over-current protection, and set the right bits to have a protection condition trip the PSU on an Over-Current fault, but the PSU will wait 20 seconds before it bothers to set the OCP bit in the Questionable Status register. I had assumed this was down to the OUTPUT:PROTECTION:DELAY being set to a default value of 20, but after changing it to a lesser value (0, 1, 2, etc.) and confirming that it was set to the new value, the PSU still waits 20 seconds before setting the Questionable status accordingly. The indication of the OCP is indicated instantly in the CURR:PROT:STAT? value, but I'd set my software to read all Protection faults via the STAT:QUES:EVEN? query, and would rather not bodge in a fix for one of the flags....
Is there something else that needs to be done to make the PSU use the new value, or am I setting the wrong values all together?
Thanks
CURR:PROT:STAT will tell you if you enabled OCP or not. If it returns a 1, that means that OCP is enabled but it does not tell you whether OCP has tripped the protection or not.
The way to see if the protection has tripped is to use the questionable status register as you are doing. The best way to check to see how it is working is to enable the current protection, then short the output. The protection should immediately kick in. If it does not, then something is not right.