Newport ESP300 & MFA stages

[James_SGP]

I am having a problem with moving the stages from the home position.

I perform a 'Find Home Signal' operation, and all the axis home ok.

When I then try and perform an Asolute Move, I get a Hardware Limit

Error and the stage stops moving. It seems to be random, as sometimes

everything is fine; after I home everything again I get the problem.

I`m pulling my hair out with this, what am i doing wrong...?

James

(Singapore)

[Albert Geven]

QUOTE(James_SGP @ Apr 24 2007, 07:51 PM)

I am having a problem with moving the stages from the home position.

I perform a 'Find Home Signal' operation, and all the axis home ok.

When I then try and perform an Asolute Move, I get a Hardware Limit

Error and the stage stops moving. It seems to be random, as sometimes

everything is fine; after I home everything again I get the problem.

I`m pulling my hair out with this, what am i doing wrong...?

James

(Singapore)

Did you test your hardware limit switches. Aren't they not reversed. Starting to move could trigger them, but I'm not sure why homing works.

Except with floating inputs?

[James_SGP]

QUOTE(Albert Geven @ Apr 29 2007, 04:52 PM)

Did you test your hardware limit switches. Aren't they not reversed. Starting to move could trigger them, but I'm not sure why homing works.

Except with floating inputs?

Albert,

Thanks for the idea, I will try and see how I can check them.

[jpdrolet]

I also have random problems with ESP300 (NI Forum Thread).

The device doesn't seem quite reliable with communications, at least with LabVIEW

Make sure that the command is completed before exiting a VI since when a VI becomes idle, the GPIB port is closed and the ESP300 sometimes hiccups on that.

Some delay between commands seems also to help.

See also Newport site on this issue

[James_SGP]

QUOTE(jpdrolet @ May 1 2007, 02:09 AM)

I also have random problems with ESP300 (NI Forum Thread).

The device doesn't seem quite reliable with communications, at least with LabVIEW

Make sure that the command is completed before exiting a VI since when a VI becomes idle, the GPIB port is closed and the ESP300 sometimes hiccups on that.

Some delay between commands seems also to help.

See also on this issue

JPDROPLET,

I'm pretty sure it isn`t a comms problem as the command is sent and begins to execute. It is the ESP-300 that then stop and gives a hardware limit error after moving about 0.1mm.

[PJM_labview]

QUOTE(James_SGP @ Apr 24 2007, 05:51 PM)

I am having a problem with moving the stages from the home position.

I perform a 'Find Home Signal' operation, and all the axis home ok.

When I then try and perform an Asolute Move, I get a Hardware Limit

Error and the stage stops moving. It seems to be random, as sometimes

everything is fine; after I home everything again I get the problem.

I`m pulling my hair out with this, what am i doing wrong...?

James

(Singapore)

I sort of remember having a somewhat similar issue with newport stages (I dont know if this was the same model though). If I recall properly, when getting close to a limit switch at a speed moderatly fast, the stage would not a accept any more commands. My workaround was to find out what was the higher speed I could use that would not generate this issue.

So you can try homing at a lower speed and see if this help.

PJM

[James_SGP]

QUOTE(PJM_labview @ May 2 2007, 09:35 AM)

I sort of remember having a somewhat similar issue with newport stages (I dont know if this was the same model though). If I recall properly, when getting close to a limit switch at a speed moderatly fast, the stage would not a accept any more commands. My workaround was to find out what was the higher speed I could use that would not generate this issue.

So you can try homing at a lower speed and see if this help.

PJM

PJM,

I tried slowing things down to 0.5mm per second, but doesn`t seem to have made much difference. I`ll play with it some more in the morning, as my brain is pretty fried today.