I am using LabWindows/CVI 5.0 I am developing a automation software for a balance. I am using SCXI 1160 for data acquisition and my balance is controlled through RS 232 communication. Now the balance cycle and data acquisition are run through a different Timer control which runs perfectly while running them manually i mean when i start the program and use the control button created for these timer to trigger. I have written a Macro for control part of the experiment and when i run a Macro my trouble starts. In the Macro at start system goes to idle state in which both balance and acquisition cycles are stopped and the Timer are disabled. After this step i am having trouble starting the Balance cycle through the Timer control. Even i e nable the Timer it doesn't trigger the functions written in the Timer Callback for balance control cycles. But it does trigger the Acquisition cycles and that works perfectly. But the Balance Cycles doesn't get started.....CAn anyone help me with this...is there any other way to trigger these callbacks.