How can I accumulate all thevalues of past error? I can do it in LAV 8.5. Cannot in Lv8.0.

[guangli]

Hi, Guys,

I try to accumulate all the past position error to feedback the motion loop. I can use this formula node in LV8.5 and 9.0. I cannot use it in LV8,0 or 8.2? In my lab pc, it's LV 8.0 or8.2. I cannot wire back the output sum to input sum. How can I resolve the problem in LV 8.0? The input variable is acquired by Machine vision Loop in real time.

Thank you!

[Jochen]

Guangli,

the feedback node was introduced with LabVIEW 8.5. In older LabVIEW versions you should use a shift register.

Kind regards,

Jochen Klier

National Instruments

[guangli]

Thank you! Actually, we don't have to use formula node inside while loop. A plus sign is enough. How can I do if the control variable is outside while loop.