Have problems of switch handshaking with DMM and other instruments

[AhGang]

Hi,
 
    In my systems, there are SMU PXI 4030, PXI Switch 2532, PXI DMM 4071.
 
    Both SMU and DMM will connect to DUT via PXI Switch. Handshaking between DMM and Switch is available yet handshaking between SMU and Switch is not.
 
    At the begging scan list including all connections (connections between SMU and DUT, connections between DMM and DUT) will be comminted into Switch.
 
   Problem is:
 
   The first 5 steps of scan list will advance with handshaking between Switch and DMM. The sixth step of scan list will be used for connecting SMU and DUT, so at
 
   this time, DMM can't shake hand with Switch and software trigger to Switch shall be used. But how can I perform this with best solution? I have 2 solutions:
 
  Solution 1:
          1) Configure sample count of niDMM Configure Multi Point as 5. DMM will stop sending trigger to Switch after measuring 5 samples (Is this configuration right? Do I need to configure trigger count?).
          2) Stop the Switch task (DAQmx Stop Task). Change the Switch advance trigger type from Digital Edge to Software.
          3) Use software trigger in the following steps of scan list.
 Solution 2:
          1) At the begging only 5 steps of scan list were committed into Switch.
          2) After DMM measurement ends, Stop the Switch task.
          3) Configure the following scan list with DAQmx Switch Creat Scan List
          4) Commit the scan list into Switch.
 
 Which solution makes sense?
 
 And another better solution?
 
Thanks
 

[AhGang]

I don't think so. Maybe I didn't describe the problem clearly.
 
There are some voltage settings change of SMU between DMM correct readings and dummy readings.
 
So DMM must stop measurement during SMU setting change. Otherwise, if DMM continue measurement during SMU setting change, switch will advance its scan list so that I can't assure SMU works on the sixth scan list. The way of stopping DMM measurement is to limit trigger count and sample count of correct readings and reconfigure trigger count and smaple count of dummy readings. The process flow is like this:
 
DMM measure 5 data (SMU is also working at this time)->DMM stops after getting 5 data, change SMU settings,reconfigure DMM,initiate DMM->DMM dummy readings and SMU working.
 
Thanks.
 

[AhGang]

Hi Patrick,
 
     Thanks for your suggestion.
 
     Can I creat 2 tasks with different scan lists at the initialization with DAQmx driver?
 
     task1: handshanking with DMM
     task2: software trigger with different scan list from the one in task1 
 
     And for the very first DMM measurment, I can use task1 with only 5 scan list steps.
 
     After that, stop task1 (do I need to clear task1) and start task2.
 
     Does this work?
 
     I would like to try but the instruments I ordered are on the way to me.
 
     Thanks.
 
     BR