Announcement

Collapse
No announcement yet.

Wengalor Laser Sensor

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Arubin@Nogah
    started a topic Wengalor Laser Sensor

    Wengalor Laser Sensor

    We are using the Wangalor OPT2001 laser sensor. We have it set up to give us an analog output. We are running it thru the analog input of a Click PLC. The voltage reading on my digital meter is very stable; however the reading in the program is extremely unstable. The laser is mounted to a rigid structure and targeted on solid fixed objects. The readings fluctuate by 0.003 0.008. The readings stay in a constant state of flux, even though there is not vibration or movement on the equipment. We have tied to tilt the sensor, adjust the multiple setting on the laser and change the types of targets that we are using. We have tried shiny metal, shiny plastic, dull metal, dull plastic, cardboard, paper and Styrofoam. There is no difference in the fluctuation of the reading. We have just, this evening tried to add different capacitors to the input as well, with no success. The laser also does not seem to always to give the correct reading either. It has been off by as much as 0.015, using the same target. We have 4 sensors and all seem to react the same. The laser sensors are fed into the Click analog input X1 which a high speed counter via the Automation Direct recommended cable that we purchased for them as well.

    I would appreciate any help that people who are using this sensor could provide.

    Thanks in advance,
    Amir

  • Do-more PE
    replied
    The laser sensors are fed into the Click analog input X1 which a high speed counter
    This part was buried at the end. So if Arubin is trying to do this with counters, then it is most likely scan time throwing things off since Click does not have true high speed IO.

    So which is it? Analog or high speed IO?
    Last edited by Do-more PE; 07-09-2014, 07:29 AM.

    Leave a comment:


  • LWgreys
    replied
    The analog voltage input on the Click is 0-5 Vdc. The sensor is 0-10 Vdc which is incompatible with the Click PLC voltage input. You would have to install one of the Analog modules to use the 0-10VDC of the sensor.

    Do this; Rewire or setup the sensor for the 4-20mA circuit of the sensor to the Click 4-20mA input. This will help in eliminating noise. One of the ADxI inputs, not X1 as this is a discrete input. The Analog input AD1I needs to be setup through the CPU Built-in I/O Setup page. From the menu bar at top select [Setup] then select [CPU Built-in I/O Setup...]. Next select the Input Tab. If you wired the sensor to AD1I (4-20mA) then set it up by selecting the 4-20mA option leaving the Input Range at default settings. Next The Scaled Range you want to use and the last item select a Data Register to store the active Scaled Analog Input value in. Once this is done then the value in the Data Register is what you use for you program Math and Compare instructions. Not X1.

    You can monitor the sensor input form the program Monitor option.
    Last edited by LWgreys; 07-10-2014, 07:57 PM. Reason: {Grammer}

    Leave a comment:


  • Tinker
    replied
    "The readings fluctuate by 0.003 – 0.008."

    What units are those? The OPT2001 sensor has a range of 30-80mm, or a span of 50mm (approx. 2 inches) 0.008mm is 1/6250 th of the span, the Analog CLICK's 12 bit ADC has 4096 discrete levels, your variation is less than one bit!
    I have found one or two bits of noise on a CLICK analog even with the input directly shorted.

    If you have scaled the input to inches, 0.008" is 1/250 th of 2" and that is rather worse than I'd expect. if you can't reduce that by wiring changes (shielded wire, solid grounds etc.) you might try some digital filtering. The CLICK does not have any built in filtering capability, but it is not hard to write a filter yourself, there are a few posts on this forum about it, sadly, the search function of this forum leaves a bit to be desired.

    Since you are using a $600+ sensor, this can't be a super low budget project, if you switched to a Do-more you could use ether a F2-8AD4DA-1 or F2-8AD4DA-2 for 16 bits (however, just one of those modules costs nearly 3 times as much as an entire analog CLICK)
    Last edited by Tinker; 07-08-2014, 08:12 PM. Reason: addition

    Leave a comment:


  • AlbertL
    replied
    Originally posted by Arubin@Nogah View Post
    ...The laser sensors are fed into the Click analog input X1 which a high speed counter via the Automation Direct recommended cable that we purchased for them as well...
    Are you sure this is correct? The Click X inputs are discrete points, not analog.

    Leave a comment:


  • Do-more PE
    replied
    If the reading on the digital meter is stable, then the likely culprit is high frequency noise. The digital meter will ignore this, but the more sensitive analog input will not. This is likely being induced into the wiring from some other source that the wiring is running close to.

    Leave a comment:

Working...
X