Using GPIB clock for Timed loop input clock source

[SnowBoy111]

I am using PCI-GPIB card to comunicate with instrument . Druck pressure Simulator

all is well , comm Ok saving ok , but My timed loop is not consistant when i use built in clock of timed loop causing inconsistant time stamps in the file like 500ms  +-40ms.

 but my desire is to at 500ms stamps exactly .

So can we use the clock of PCI-GPIB Card to source the Timed loop?

initially i posted the message in labview forum http://forums.ni.com/ni/board/message?board.id=170&thread.id=293301 "timed loop executes before "period"" have a look for background sequence thanks

[Ted_H]

Hi,

Unfortunately you cannot use the clock on the GPIB board to source a loop in LabVIEW, the NI-488.2 drivers simply don't provide this functionality.

What are you trying to do deterministically every 500 msec? Or, are you simply using the timed loop as a means to pull off a timestamp? Unfortunately Windows based systems as well as GPIB and other event-based communications are not deterministic.  If you are trying to take regular, periodic measurements, your instrument should have command where you can specify such an action.  Refer to you device's programming manual for this information.

Please feel free to post back with any additional questions.

Ted

[SnowBoy111]

my objective is that saving a file should have a time stamp of 500ms or any other but exact.

my code ends with in 500ms . can we wait a more like 50ms on the next frame setup in Timed while loop  . so that first frame will execute

<=400ms +-40ms and second ll execute in 50 msec to compensate rest of time

[Ted_H]

Have you tried using a flat sequence structure with timing VI's to control the execution of each frame?  This should provide you with the timing your a looking for, and is particularly useful when programming instruments.

Ted