Multiplexer, DMM and Power Supply order and timing.

[GSinMN]

Hello All,

 I'm developing a testing application (TS 2013 and LV 2013) that will use a 4070 DMM, 2527 MUX, and a variable power supply.  I do alot of switching between powered voltage checks and unpowered resistance checks, but I try to keep the same "template" for the sequence, so it is modular and reusable.  Generally, I have been configuring the routing, initializing the DMM, then activating power and triggering a measurement.  I've been analyzing the sequence to improve efficiency, and thought it may be better to initialize the power supply (and let it run asynchronously) before the DMM.  My concern of course is having live voltage at the test leads of the DMM before it is initialized.  Would this be safe for the equipment?  I haven't seen anything in the data sheets that specifically addresses this.  I've also read some of the white papers on the NI site related to DMM Measurements, but haven't found anything there either (found plenty of other good info though).  Please advise. 

Thanks in advance.

GSinMN     

[crossrulz]

If you set the DMM to do Voltage measurements before switching off of the resistance that was measured, I don't see any real issue here.  My only concern is that the DMM actually sources a current when performing a resistance measurement.  You don't want to have your DMM sourcing a current and having your power supply source a voltage to the name electrical node.  Some really weird things are possible in that situation.