500kbps problem of sick lms

[Grace12]

Hi,

I guess I'd better posting the message in a new thread instead of a reply. I am trying to make the Sick LMS291 work under 500kbps. However, it seems the VISA configure serial port vi cannot work under this baud rate (error code -1073807330)... although it works by the Sick software. The way I achieve 500kbps is using a serial to Ethernet convertor. I don't quite understand why but, according to Sick, by configuring this device with 9600bps it can work at 500kbps... communicaion can be made under all the standard baud(9600, 19200, 38400) using this setup, only except 500kbps... I searched in the forum and did not find much discussion about this communication issue. Please help me. Thanks!

[NathanT]

Hello  Grace,

       Here are some online documents and other Discussion Forum posts that might help:

VISA Configure Serial Port Yields Error -1073807330

DF Post

Let us know how it goes,

NathanT

[Grace12]

Thanks, Nathan!

In the manual of the serial to Ethernet convertor I am using, it asks me to set the baud rate to 300 in Internet explorer in order to get 500K modulation speed. So I just changed the baud rate to 300 for the VISA Configure Serial Port vi as well as the setting in windows Device Manager. However, though I am able to collect data using the program above, the speed doesn't look like 500k at all... even much slower than I did it in 38400 bps. Any thoughts?

[NathanT]

Hello Grace,

      As far as I know, if you configure a regular serial port for 300 baud, then it will be configured for 300 baud.  The instrument has commands to configure its baud rate.  I have not heard of virtual COM ports that require you to set the baud rate in a non-intuitive fashion.  Can you please post the model and manufacturer of the serial to ethernet converter?

Thanks,

NathanT

[spsuamin]

Has there been any more progress on this thread?

I am working with a LMS291. I was able to use the driver examples and get the provided vi to work but of course I required the 500,000 baud rate to get the most out of the unit. I was planning on replacing each of the serial communication vis with tcp/ip communication protocal. Any thoughts by anybody?

[pflores]

Some of our Serial cards allow you to communicate at non-standard baud rates. Would this help?

[Grace12]

Sorry guys, I quited working on this problem for about half an year and I picked it up recently. Thanks very much for your previous help!

It is working now. I am using Comtrol DeviceMaster500 to convert RS422 to Ethernet in order to achieve that non-standard 500kbps. This device is recommended by SICK, but I guess some other devices with lower cost should also work, not necessarily have to be a ethernet connection.

I am now debugging the LabVIEW program. Anyone who had made it work or is working on it can share your experience here 

[RIObotics]

Hi Grace,

Congratulations on your success on making the LMS 291 to work at 500kbps!  Our lab is trying to replicate the same LabVIEW setup with 500kbps, but with no luck so far.  I just have some questions for you, I hope you can share some of your experiences:

1. How did you solve the error code -1073807330 problem that you had before?  Did it just go away?

2. What baud rate did you use from LabVIEW?  Was it the actual baud rate of transfer, or did you have to set it at 300?

3. Besides the jumper between pin 7 and pin 8, were there any special pin rewirings on the 9-pin connector on the LMS 291 side?  Right now I'm following the pinout diagram from SICK's manual (see diagram.)

Thanks very much for your help!  We have been stuck at 38400bps for a while, hopefully we can get up to 500kbps.

-John

[Brian_Beal]

It has been several years since my LMS project, but here is what I remember.  I used a PCI serial card from B&B Electronics, and put in a different crystal to get the 500k speed.  I forget the exact numbers, but I used a ratio of the standard crystal to the one I used to "move" a standard baud rate up to 500k.  I think I just picked 460,800 as the baud rate, but it was really 500k.

I recall seeing 2 different pinout diagrams.  One was in the full manual, and the other was in some kind of install manual.  I don't remember which one was wrong.  I think I still have the info at home, and will try to check tonight.

[RIObotics]

Thanks Brian, although I am hoping to find a off-the-shelf solution for the serial/ethernet interface.  I'm not too confident I can replace crystals.  Thanks Brian.  My ultimate goal is to get the SICK LMS291 working at 500kbps with the serial port of a sbRIO, so that's why I haven't looked much into PCI interfaces.

-John