Error 6 being generated while using ESP300 controller

[DavidGwyther]

Hey guys,

I'm using an ESP-300 motion controller to drive an ILS-150CCHA stage.  I'm trying to get the stage to oscillate backwards and forwards with decreasing amplitude.  However, I'm finding after a certain amount of time, the stage just stops.  The program (labview 8.0) says that error 6 has occured.  I've searched for related topics here, but found they didn't answer/solve my problem.

The program works by sending a series of absolute positions for the stage to move to, separated by 'wait for stop' commands.  For example, move to 10, wait for stop, move to -10, and so on.  After about 80 or so, movements, movement will cease.

Also, it may be unrelated, but while the stage is moving, the controller beeps - Which I'm lead to believe is because an error has occured?

I understand this is a NI forum, not a newport forum, but I think error 6 relates to a GPIB read/write error?

I'm communicating via GPIB.

Controller: ESP300 vers. 3.08

Stage: ILS150CCHA

Many thanks in advance,

David G.

[Albert.Geven]

Hi

error 6 points to a timeout. In other words the Esp300 has stopped to communicate.

Which driver do you use to communicate.

Can you see an error light blinking on the esp300 or do you have an error message when asking the controller?

But I'm afraid you have either a hardware problem (too much power needed for this function) or too much slip between controller and hardware

But first which low level software do you really use to communicate?

[Burban]

David,

I want to echo what Albert posted as far as this being a timeout related error.  Have you seen this resource on GPIB error codes?

GPIB Error Codes and Common Solutions

Regards,

[DavidGwyther]

Hey guys, thanks for the replies.

In device manager, my PCI-GPIB has driver version 2.4.0.3500.  Is that what you're asking?

For a while the esp300 would beep intermitantly, throughout the movement process, display error 6 - command does not exist. This is strange - the commands I am using are WS (wait for stop) and PA (move to absolute position), and I've checked the string that is being sent to the ESP300 for any wrong commands (there isn't).

Now however, the beeping stopped, as I decreased the number of digits after the decimal place for the distances to move (i.e. move 3.5 instead of 3.498, etc).

I can't help but think it may be a buffer problem - as the stage will move 82 times, and then cease movement.

I'm using labview 8.0 (is that what you mean by low level software?).

I checked out the list of GPIB error codes, but I can't see how that is the problem, I've made sure an EOS character is being sent.  In any case, I can't see why it would stop at the 82nd command, as if I replace that command with a different position, it will still stop.  So it seems to be basically independent of the command, and rather, by the 82nd command, something happens (e.g. buffer is full???)

Thanks guys, appreciate the help!

Dave.

[DavidGwyther]

I might just add that I've updated to firmware 3.09, but the problem persists.

Now, when I run the program, errors seem to be being generated intermittently.  I checked in the error log on the ESP300, and the errors are: command does not exist, command parameter missing, axis missing.   As I can see the concatenated string that is being sent to the controller (and none of these are true ^^^^^ ), perhaps there is data getting lost during transport from the computer to controller.  E.g. 2PA10 is sent, but the A is 'lost' and 2P10 is read?

Cheers

Dave

[Albert.Geven]

A complete library of LabVIEW™ drivers covering all ESP300 commands and communication DLL’s covering all the most popular Windows versions are available and continually updated and accessible at www.newport.com.

This is what I mean with low level drivers.

And GPIB is very reliable, but maybe you are sending two commands at almost the same time or not waiting to read the result?

Can you show how you architected your software?

[DavidGwyther]

I've been in contact with a engineer at Newport, and they seemed to think that it could be a problem with their not being a long enough delay between sucessive queries, leading to an overloading of the buffer.

I'm going to try and add a delay, and see if that helps.  Though, I'm not quite sure how I will do this.

As for the program:

I generate a concatenated string of ESP300 commands, which are sent to the ESP300.  I've attached a picture showing the send protocol, and the actual ESP-send sub-vi.

Thanks for your ongoing help 🙂

[Albert.Geven]

Hi

I would send each comand in a separate string, and wait for response when necessary.

Furthermore I advise to use the visa software for sending and receiving.

And have a look at the instrument driver from Newport.

[Burban]

If you are looking to add a delay between the send and recieve, here is a good way in which to do that.  I've used VISA to illustrate in the screenshot that I have attached.

[Albert.Geven]

Hi Ben

Just out of curiosity Why didn't you use jsut a one frame sequence.

The only one needing a frame is the one that contains the delay.

All the other calls are already sequenced by wire.