Keithley 2750 Multimeter and 7702 MUX card -221 "settings conflict"

[jkenda]

I am programming the 2750 multimeter with a 7702 MUX card and 3740 relay card for a product testing machine.

Here is the code:

Code: Select all

ROUT:MULT:OPEN (@101:142)
SENS:FUNC 'RES', <clist>
ROUT:SCAN  <clist>
SAMP:COUN 5
ROUT:SCAN:TSO IMM
ROUT:SCAN:LSEL INT
READ?
ROUT:MULT:OPEN (@101:142)

I get a -221: "Settings conflict" error when running the code multiple times while measuring different channels.
When I was opening the channels with ROUT:OPEN:ALL, everything was fine, but now I get the mentioned error.

The thing is, I cannot use :OPEN:ALL because that would also open the relays, which is not an option because testing machinery will be hooked up to them. But I am opening all channels of the MUX before the measurement, so I don't know why I get the error.

How could I modify the code to make it work?

edit:
I have working TSP code for this functionality, I would just like to implement it for a multimeter that doesn't support TSC.

Code: Select all

scan.mode=scan.MODE_OPEN_SELECTIVE
...
scan.create('<clist>', '<configuration>')
state = scan.execute(buffer)
printbuffer(1, buffer.n, buffer)
buffer.clear()

The scan works in TSP because of the scan.MODE_OPEN_SELECTIVE, which opens all the measurement channels but not the relay channels. I cannot seem to achieve the same with SCPI.