movement

[bcg]

Hello,
New at labview, old s/w (5.1):

i have 2 transducers each in multiaxes acquisition programming.

Question: how to change 1st transducer move first before the 2nd

issue:
1) if i have 2 transducers, say T1 & T2, moving in the x-direction, for example, and
2) i have only one x line to collect data and it finishes, (since only 1 line, then its the last line)
3) then T2 moves before T1 which is ok.

problem:
4) if i have multi lines, say in the x-drection,
5) then, T1 moves to the new starting position before T2.
6) and when on the last line, just like 2) & 3), T2 moves back to the starting position before T1.
7) i want T2 to move each and every time before T1, not just when it's moving back to its starting position after finishing the last acquisition line.

is this an easy program change or a deeper problem.

Hope I gave enough information. Thanks for your understanding & help!

Byron Golden
Allied Geophysical Labs
U of Houston

[johnsold]

Byron,

I read your post twice but still do not understand what you are trying to do. I am confused about transducers T1 and T2 and last x lines and what is OK and what is not.

Are you measuring the position with the transducers or are they the devices which generate the movement?

How many data acquisition channels do you have, input and output?

How fast are you sampling inputs or updating the outputs? How many samples on each acquistion?

Is this a closed loop controller or simply a monitor or position driver?

What are you doing with the data input or how are data outputs generated?

LV 5 was/is powerful software, but the list needs to have a better understanding of what your problem is before someone here will be able to help.

Lynn

[bcg]

Hello Lynn,
I thought you may need more information. The problem is I didn't write the code and I certainly don't know Labview.

I'll try to add as much information as I know.

i'm trying to modify postioning/movement only.

I have a mechanical-movement scanning system consisting of 2 transducers, 1 source, 1 receiver, that each can move in x,y,z planes. A transducer is both a uhf sender and receiver. one can be assigned as a receiver, and the other aa a sender. The data collection occurs in the water over a surface.

stepper motors move wires and poles to which the transducers are attached.

I want to program movement of the source and receiver, no problem.

Right now, I have the source and receiver moving in the same direction, where the source moves first, otherwise the receiver will run into, physically touch the source.

current and corrrect data collection pattern is like this: source moves away from the receiver, stops, receiver moves toward receiver, stops, data collection, then repeats until the last point of data collection. Say 5 points are collected, then the movements will occur 5 times.

everything is fine until it finishes.

when the 5 points of data are collected, the source wants to move back to its original x position, toward the receiver. the source will physically touch the receiver, and damage may result.

I want to modify the movement where the receiver to move first, away from the source and toward the starting position, and the source after the receiver moves.

I want to collect multiple lines and I can't because the source will physically run into the receiver.

Or think of it this way,

You and a friend are standing in line. He is in front of you he takes a step forward and stops, then you take a step forward and stop. You and he continue this multiple times.

Now, let's say he wanted to return to the point where he first stood in line. He can't because you are there. For him to get to his original position, you will have to move back to your original position before he does to avoid him walking into you.

I don't know if this explanation cleared any confusion.

thanks!
Byron Golden

[nipun]

Hello Byron,

Thank you for using our discussion forums. From your description of the problem it sounds like the setup is working correctly except for the last move, where you want one of the transducers to move to its original position before the other. In other words you want to modify the last phase of the trajectory followed by the two transducers. This should be an easy modification to make and you are in luck since LabVIEW is extremely easy to learn. So feel confident and open up the VI and look at its block diagram (To look at the block diagram select Window>>Show Block Diagram). On the block diagram there will be a VI named Load Target Position.flx. Now, an easy way to search for VIs is by selecting Edit>>Find. For the select object option click on the icon and select the VI you are looking for from the Functions Pallet. In this case you can find Load Target Position.flx under Functions>>NI Measurements>>Motion>>Flex Motion>>Trajectory Control. This VI is the one that loads in the target position. Look at the inputs to this VI and modify them to change the last part of the trajectory. I hope this helps you out. Have a great day!

Regards,
Nipun M
Applications Engineer
National Instruments