Hokuyo URG-04LX-UG01 and CompactRIO 9076

[JArlidge]

Hi

I am trying to use the Hokuyo URG-04LX-UG01 LIDAR with my cRIO 9076 via the on board USB port and am having problems getting it to detect the LIDAR. I can use it plugged into my laptop but when I change the VISA option to cRIO-USB from the example from labview I am unable to detect the scanner. I have tried rebooting the cRIO while it is plugged in and no success. Any help would be greatly appreciated.

Thanks Jackson

[Ben-N]

HI Jackson,

Are you using a a driver that was built on USB raw or USB TMC protocol?  Most real time operating systems do not support USB TMC communication, and require that any communication at all that is performed through a USB interface is handled as USB raw.  Windows on the contrary is able to handle both types of communication, which would explain why it works on your laptop but not on your 9076.  The vi you posted was broken because it looks like some of the VIs for that device are included in subVIs.  Is the driver something that came with the hardware or something you acquired elsewhere?  You are going to want to confirm that the driver is compatible on a real time operating system, i.e. that it is written using the USB raw protocol.

[JArlidge]

The sub vi's are part of the robotics suite (also availabe here: http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=501C4A2F62792566E0440003BA7CCD... and they have the option for rio-usb so assumed that it was the correct format

[Ben-N]

Hi Jackson,

The link you posted is broken.  Are you referring to the generic Hokuyo URG-04LX LIDAR driver?  Is this the driver you are referring to?  Looking at the readme file for this driver, it looks like the URG-04LX is supported in SCIP 2.0 mode only.  Additionally, what version of VISA do you have installed on your CompactRIO?  I don't see that it specifically states that this driver was designed for your LIDAR device.  Does the -UG01 indicate some additional functionality compared to the standard 04LX series?  I didn't see on the driver page where it mentions rio-usb communication.  Can you point me to where you were looking at this?

[Brian_Powell]

[Edited post, because the link went to a private discussion forum the AEs used.]

In short, we are aware of an issue, and I'll post more.

[Brian_Powell]

Here's one recipe that might work, starting with the Hokuyo example from LabVIEW Robotics...

1. Add the RIO as a target to the project.

2. Move the example VI and place it under the sbRIO target.

3. Open the VI and change the Polymorphic Instance on the Initialize VI to "cRIO-USB" This results in a broken wire to the VISA resource name.

4. Delete the VISA resource control and create a new one from the input to the Initialize.

5. In MAX, find the sbRIO and look at the USB devices under Devices and Interfaces. You will see two resources there. Select the second one.

At this stage you will find a string of the form "10.0.39.170/USB0::0x15D1::0x0000::NI-VISA-0::1::RAW". This string will end with 1::RAW so scroll if necessary to get the full string.The first part of this is the IP address which will need to be taken out when addressing this device from the RIO. So we end with a resource string of the form "USB0::0x15D1::0x0000::NI-VISA-0::1::RAW". 

6. Paste the resource string from above into the VISA resource control in the example and it should work without a problem.

Troubleshooting possibilities

-Is the VISA USB passport installed on the RIO? You should be able to see it under the RIO at Software->NI-RIO->NI-VISA->NI-VISA USB Passport. Without this USB functionality will not work on the RIO.

-Note that setting an alias in MAX only works for "My System" i.e. it will resolve to the correct resource for VISA calls made from that computer it does not set the alias on the RIO.

Let us know whether this works.

[JArlidge]

I have tried this but cannot see the USB in MAX, here is a sreen shot of what I have in MAX. It shows that I have the usb passport installed

[Ben-N]

Hey Jackson,

I'm also having some trouble getting this description to work on a cRIO 9076.  This specific process was discussed for use on a sbRIO  I'll follow up with Brian to see if we can't figure out what's going on and hopefully get all this sorted out shortly.  Thanks for being patient with us and we will get this sorted out as soon as we can.

[JArlidge]

Any luck yet? would love to be able to carry on with my project

[Ben-N]

Hi JArlidge,

I've looked into reproducing your setup here, but I've run into some problems getting a hold of one of the Hokuyo LIDAR systems.  I've been in touch with one of our developers that does have access to this device to try to replicate what you are seeing, and we are still in the process of reproducing the issue. 

Based on several discussions I've had with my colleagues, we have been able to use this LIDAR device with both our CompactRIO and sbRIO devices, and the device comes up under the RIO device as VISA RAW resources.  However, this will only occur if there is a USB RAW device plugged into that USB port.  Do you have access to another CompactRIO device to try this on in the mean time?  Additionally, you may want to try completely reformatting your cRIO and reinstalling the software to it.  It may be that the installation was not complete or that an error occurred during the installation.

As soon as I hear back from our developer I will get back in touch with you and let you know if we are able to reproduce the behavior you are seeing.