how can i control the motor movement of stepper motor using a NI PXI 7330

[Jochen]

Tikoy,

it sounds like the wiring and the configuration are correct. Have you checked if the reed switch opens and closes correctly (please measure this with a DMM). Please check the status of the limit switches in MAX (1D-Interactive).

Just for a test: Do you see a change if you exchange the reed switch with two wires that you can connect manually with each other to simulate a mechanical switch?

Thanks,

Jochen

[Tikoy]

Good day Sir Jochen,

I've already check the status of the reed switches in MAX and they respond accurately. I've also exchange them with mechanical switches but still get the same result. Right now, my forward limit reed switch function as the home and my reverse limit reed switch works as the emergency stop. If the Motor reached the forward limit, the position will be reset to o because i'm using the "absolute position mode".

Thanks

[Jochen]

Tikoy,

I'm a bit confused now. Are the limit switches working now or not? If you see their status changing in MAX, there is no way, that the axes don't stop when they reach the limit switch. What behavior do see exactly? Keeps the axis moving just for some steps and does it stop later than you would expect it to stop? This could be caused by the axis' inertia and all you could do against that is setting software limits at some distance before the limit switches to decelerate the axis before it hits the limit switch.

I also don't understand exactly how you have wired your fwd limit switch. Is it wired to the fwd limit switch input or to the home switch input? In both cases the axis' position wouldn't be reset to 0 automatically during normal moves. Are you using "find reference" for this purpose?

Thanks,

Jochen

[Tikoy]

Good day sir Jochen,

Sorry for the confusing reply statement,

The above statement is only my plan for the program . it is not yet implemented and not yet working.

I only wired the forward and rverse limit and no home input because i only have 2 reed switches.

the motor won't stop when it reaches the limit switch. it will only stop when it reached the desired position. For example, when the motor is in "0" position and it is near a limit switch, and then i input "-10000" for the position, the result is it still move to the"-10000" position even if the motor pass through the limit switch. I expect that the motor will stop and will not complete the movement because it pass through a limit switch

Right now , I am using a program based on the Simple one-axis move.vi example found in Labview example finder and added some function like the velocity control.

Thanks,

[Brian_Beal]

An axis should (almost)never be able to pass through a limit switch.  The limit switch should be active until a hard stop is encounterd.  Not sure about the NI controllers, but most motion controllers will start to decel when a switch is encountered but will resume the move if the switch is no longer active.

[Jochen]

Tikoy,

I have never heard of a 73xx device that doesn't stop the axis, when a limit switch is hit. Please use 1D-Interactive in MAX to verify this behavior. If the limit switches are activated and if you can see the the limit switch changing in 1D-Interactive and if the motor doesn't stop, there seems to be something badly wrong with your board. In this case please contact your local NI branch for further investigations. I don't see further options to debug this through the discussions forum.

@Brian,

the default behavior of NI 73xx motion control boards is to halt the axis immediately when a limit switch is hit. This behavior can be changed to decelerating or killing the axis. The move is not automatically resumed if the limit switch becomes inactive again, but the user or calling program is notified about the limit switch status.

Regards,

Jochen