DMM7510 in 4W RTD outputs a square wave signal that affects Fluke Calibrator during calibration.

DMM7510 in 4W RTD outputs a square wave signal that affects Fluke Calibrator during calibration.

The reason there is what appears to be a square wave output when the RTD temperature measurement is turned on is because offset compensation (OCOMP) is enabled by default.
For 4W Ohms it is disabled by default. I switched this off for the 4WRTD function and measure the constant current with a second DMM. Likewise, if I set my measure function to 4W Ohms and enable OCOMP then I see the pulsed current output.
So disable the Offset Compensation during calibration.
Press TEMP in the main window.
Press MENU.
Select Offset Compensation.
Select OFF.