Use of Square Wave Generator on DMM

HOw did you come up with the 4-20 ma loop option ? Most 20 ma loops are setup to use about a 24 volt supply. Some of them will have a 250 ohm resistor in them to convert the 4-20 ma to a 1 to 5 volt signal for the readout device. This takes atleast 5 volts. The loops usually work on DC. I have used some test equipment that will ramp up in steps of 25% but it is much slower than 30 hz. Maybe every .5 to 1 second. I have used some VOMs that have a miliamp driver built in. Fluke makes one.

I am sure there are applications that require that 2 volt square wave signal, but I have not seen any. What else does the meter do ?

maybe that is part of a 4..20 ma output option to calibrate devices?

because my meter has a pulse generator as a signal along with a 4..20 output to be used in calibrating current controlled devices. its used to supply a signal into the control device or to actually pulse the "ma" output line to pulse the actuator it self. its programmable. also, my meter uses a 9 volt source but has a DC-DC converter to generate 24 volts for the current source with scale able current out and monitoring.

i don't know the meter that is in use, only going by my experience and suggesting what it could be.