How to soft trigger a DS457 Zebra scanner in Labview

[Harm_Le]

Hello,

I am using a DS457-SR20009 Zebra/Motorola scanner with a USB connection that is emulating a Serial port, which I can connect to Labview via a VISA. And this works, there is a button on the scanner that when i press it, the barcode outputs as a string in Labview itself.

The integration guide for this scanner is located here: https://www.zebra.com/content/dam/zebra_new_ia/en-us/manuals/barcode-scanners/fixed-mount/ds457/ds45... 

But what I am trying to achieve is that I can somehow soft trigger the scanner so that no physical button needs to be pressed, it is needed for automating my process. I read somewhere that scanning the barcode to Host trigger mode (in the integration guide) makes it so that the scanner is no longer trying to read whatever is in front of the scanner but waits for a trigger to scan, whether that's the physical button or when a trigger event is activated (Host trigger is the same as Level trigger, the only difference is that the physical button is also useable). 

Any help would be greatly appreciated,

Harm

[l.hovs]

Hi Harm_Le, 

Did you check VISA Assert Trigger Function before? 

This faction can help you to make soft trigger. For software triggers, Default (0) is the only valid protocol.

Here is more information about this VI.

Regards) 

______________________________________________

Best way to thank is giving a Kudos/Marking as a solution

[Harm_Le]

Hello I.hovs,

First of all, thank you for your reply!

I actually did stumble upon this, I have tried to use it in the simplest form I could come up with (See attached Vi), but got an Error message and don't know how to resolve this (I am by no means an advanced programmer after all):

Error-1073807302 occurred at VISA Assert Trigger in VISA_Assert_Trigger.vi

Possible reason(s):

VISA:  (Hex 0xBFFF003A) Unable to start operation because setup is invalid (due to attributes being set to an inconsistent state).

Best regards,

Harm

[JimB.]

The Assert Trigger function is not relevant. These barcode scanners do not conform to such test instrument standards.

What host mode are you using? Default (SSI) or have you switched to one of the others?

I don't think soft triggering is possible in the "Standard RS-232" mode. If this is the mode you prefer to use, then I think you may need to use an external trigger. See p.36 and 38. To automate this, you'd need to something else with a relay output (or similar) to actually do the triggering.

To use soft triggering, I think you need to use SSI over serial:

https://www.zebra.com/content/dam/zebra_new_ia/en-us/manuals/barcode-scanners/software/ssi-corded-pg...

Alternatively, SNAPI over USB.

[l.hovs]

Hi again, 

Try to follow this article to solve this error, the solution to this error is pretty well described there.

Regards)

[rolfk]

---

@l.hovs wrote:

Hi again, 

Try to follow this article to solve this error, the solution to this error is pretty well described there.

---

A scanner is NOT a T&M device and does not conform to IEEE 488.2 command specification. As such the Assert Trigger or Read Status Byte function in VISA has no useful effect on it. The OP needs to find the device specific command to send to the scanner to achieve this operation.

Since these devices are designed to work with rather dumb or very limited to change devices such as cash registers and similar, the methods they support on RS-232 and other interfaces are very limited.

As Jim explains you will either need to use SSI over serial or SNAPI over USB to be able to have some real programmatic control of it.

[AnalogKid2DigitalMan]

Why not use Presentation mode where it is looking for a barcode in its field of view all the time and automatically triggers when one is presented to the scanner?

-AK2DM

[Harm_Le]

Hello Jim and rolfk,

I think you guys are right, when I put it in SNAPI mode I can open SDK software from Zebra and there is a Soft trigger button that works. And it doesn't work when I emulate the USB to a COM/Serial port, which is needed to use VISA.

But how do I implement this SNAPI mode in Labview? Is there a SNAPI equivalent of VISA available in Labview or am I thinking in the wrong direction at this moment?

Best regards,

Harm

[Harm_Le]

Hello AnalogKid2DigitalMan,

The scanner is moving on a CNC machine, and I don't want to scan everything it sees only the correct subpanel datamatrix code in the correct order.

Also when the scanner moves in front of a datamatrix code it doesn't always recognize this. When it isn't in Presentation mode, and I press the physical button when it is in front of a sticker it sees it 100% of the time (so far) so it is much more reliably which is what I am looking for.

Best regards,

Harm

[Harm_Le]

Hello Jim and rolfk,

I think you guys are right, when I put it in SNAPI mode I can open SDK software from Zebra and there is a Soft trigger button that works. And it doesn't work when I emulate the USB to a COM/Serial port, which is needed to use VISA.

But how do I implement this SNAPI mode in Labview? Is there a SNAPI equivalent of VISA available in Labview or am I thinking in the wrong direction at this moment?

Best regards,

Harm

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