Counting People FAQ

Video Turnstile
People Counting Systems from Biodata Ltd

Technical Support for Video Turnstile

If you are having problems with your Video Turnstile system, these notes should help you determine the solution.

  1. No Counts are Recorded and the Up and Down Lights on the VT Module Flash Regularly
  2. The System is Under- or Over-Counting
  3. A VT Module is Missing
  4. You Cannot get Reliable Communications with an LVT over Ethernet
  5. Using Hyperterminal to talk to an LVT module
  6. You have problems connecting an LVT over RS485
  7. The computer cannot talk / connect to the eLVT
  8. VT unit stops uploading the data but is counting fine in VTsetup
  9. The zone lines keep flickering and moving generating false counts
  10. When you change the epoch time the last value returns several times
  11. The clock thinks it's 1970
  12. The data was being collected regularly and suddenly no counts are generated after running VT collect
  13. The diagnostics 770 box is showing all different colouring blobs within the Yellow grid and not allowing analyses of a single person to be shown clearly
  14. The eLVT box is found by the Lantronix software, it can connect in VT setup and is fine. However, we could not get any data from the eLVT
  15. The VTcollect Service stops but Windows Control Panel says it is still running
  16. The message "Error reading settings - attempting to restore defaults" has appeared.
  17. Another Problem?

Key:
VT: Video Turnstile
LVT: Logging Video Turnstile

1. No Counts are Recorded and the Up and Down Lights on the VT Unit Flash Regularly
This indicates that there is no video signal going into the Video Turnstile unit. Although the lights flash briefly, the counts are not incremented. You need to determine why there is no video signal:
  1. Check the cable connections between the VT unit and the camera.
  2. Check with a multi-meter that 12 V DC is available at the camera end of the cable.
  3. If you have more than one LVT or VT unit, swap the connection to the VT with another camera that is working.
2. The System is Under- or Over-Counting
If you find that the system is regularly under- or over-counting, you can make adjustments in software to suit the settings to your site. For under-counting you can, for example, increase the sensitivity of the people detection by adjusting the camera height setting. You can also adjust the minimum gap detected between people, alter the size of an object which is to be considered a person, alter the crowd counting settings, or, if all else fails, adjust the count by applying a scale factor. For more on the making adjustments for under- or over-counting see the User Manual or the on-line Installation Guide. You might also find it useful to view the raw count data - see the Installation Guide for details.
3. A VT Module is Missing
If an LVT module, in a group of modules, suddenly disappears then the address of that module has probably been changed. This may be due to an electrical transient, in which case the address has probably been reset to 0. You may then have two modules with address 0.
 
Use VT Setup or Setup800 software to find which module has lost its address. You may need to disconnect all the LVT modules and reconnect them one at a time to identify the correct one. Having found it you can use VT Setup (or Setup800) to re-enter the address of the module. For more details see the Video Turnstile User Manual.
4. You Cannot get Reliable Communications with an LVT over Ethernet
Check with Hyperterminal that you can talk to the module (see below for details). Follow the steps to Request the Hardware Type. Did you get back the correct reply?
  • No: You need to check the setup of the Lantronix virtual COM port and the Ethernet connection.
    Use the Xport Installer program to check the setup.
    Use the Search button to get a list of LVT units (and any other Lantronix Xport devices) on your local network.
    "Ping" the LVT unit to confirm that there is a network connection to it: click the Ping button and enter the IP address of the LVT unit you want to check. The response time for communications with a locally connected LVT unit will typically be 0 msecs.
  • Yes: Wait 10 seconds then repeat the steps to Request the Hardware Type. Did you still get back the correct reply? If not your LAN is probably routing your messages out to a WAN, as well as to the LVT. Check the GATEWAY setting with your network manager.
5. Using Hyperterminal to talk to an LVT module
Load the Windows Hyperterminal program (c:/program files/accessories/hypterterminal/hypertrm.exe) and set up the communications as follows:
  Connect To tab
    Connect using:
      Direct to COMx 
      (where x is the port number to which your 
       LVT is connected.)
    Configure ...:
      Bits per second  9600
      Data bits        8
      Parity           None
      Stop Bits        1
      Flow Control     None
  Settings tab
    Ascii Setup ...:
      Ascii Sending
        Echo characters typed locally - Checked
        others as default	
      Ascii Receiving
        Default settings
You should now be able to communicate with a module over the serial link created. To request the hardware type you need to know the address of the module with which you are trying to communicate. The default address for a single LVT module is 0. (You can check and change the module address using the VT Setup (or Setup800) program. Details of using this are in the Video Turnstile User Manual.)
 
Using Hyperterminal to read the hardware type for a module with address x you need to type:
 *x DCO HT
 (and press Enter)
 the reply will be:
 x: ML825
 (possibly followed by another letter)	
 
 e.g. for address 0
   you send *0 DCO HT
   and get back 0: ML825
You will not get a reply if:
  1. There is no communications link between the PC and the LVT - check the cable(s)
  2. You have sent the wrong address - check with VT Setup
  3. The LVT is not powered
6. You have problems connecting an LVT over RS485
  1. Try to arrange a local RS485 connection from your PC. Bring the LVT modules one-by-one to this local connection.
  2. Use the VT Setup software to change the address of each LVT module in turn. LVT modules are sent out with default address 0. If you connect the LVT to your RS485 link, and power up the LVT, VT Setup should find it at address 0. You will need each LVT on an RS485 connection to have a different address. Start from 1 and work up. It is best to leave address 0 free so that you can add a new LVT to your system and find it while all the others remain connected.
  3. If you do not arrange a local connection, check each LVT in turn. That is, go to the nearest LVT to the PC with only a single section of cable between the PC and LVT, and disconnect the rest of the LVTs. Check the continuity of the cable by twisting the Tx+ and Tx-, and the Rx+ and Rx- wires at one end of the cable section and using a multimeter to check continuity at the other. You can then check continuity of a new length of RS485 cable and attach it to the 5-way screw terminal block.
  4. RS485 cable should be 2 twisted pairs + screen. Use:
    1 pair for Tx pair
    1 pair for Rx pair
    and screen for signal ground.
7. The computer cannot talk / connect to the eLVT
The computer has to be on the same subnet mask as the device (eLVT). Run the Device Installer to check, and if necessary change, this on the PC. See the Installation Guide or User Manual for details.
8. VT unit stops uploading the data but is counting fine in VTsetup
Reset the clock. It won't collect any epochs for 18 hrs if it has been reset, but will run and initially not give any data.
9. The zone lines keep flickering and moving generating false counts
VT module in a Rack system - short out with a link wire, R21
Boxed VT or LVT unit - short out with a link wire, R38 (R38 is located between the R37 and C39 labels visible on the board)
10. When you change the epoch time the last value returns several times
The epoch time was changed at the same time as the clock updated. This led to the update being ignored. Leave a gap between these times to stop this occurring.
11. The clock thinks it's 1970
If the unit is un-powered for some time the internal battery will run down and the internal clock will reset to 1970. On re-powering the unit you need to set the clock to the correct time using VT setup. (The battery will require about 30 hrs on charge before it is fully recharged.)
12. The data was being collected regularly and suddenly no counts are generated after running VT collect
  • The power supply to the eLVT may have been disconnected. Check this by connecting to the eLVT and the LED lights should flash.
  • The camera may be faulty, check to see if there is still a picture generated by the camera and if there is power to the camera.
  • The video cable or RG59 cable may have been disconnected between the camera connection and the logger connection.
  • The logger unusually may have a fault which a replacement unit will identify.
13. The diagnostics 770 box is showing all different colouring blobs within the Yellow grid and not allowing analyses of a single person to be shown clearly
  • It takes time for the coloured blobs scattered in the yellow grid to blend into the background.
  • The time this is determined by the freeze time. The lower the freeze time the quicker the blobs disappear.
  • To proceed stop and start the 770 box.
  • Start the analyses once the grid is all yellow and then analyse the transits.
14. The eLVT box is found by the Lantronix software, it can connect in VT setup and is fine . However, we could not get any data from the eLVT
Check the power supply to the box. It must be a 12 V DC supply. The ethernet circuit runs off 3.3 V but the rest of the circuit requires the full 12 V, so it is possible for the ethernet to be working but not possible for request for information to get through the logger section.
15. The VTcollect Service stops but Windows Control Panel says it is still running
If the VTcollect service sometimes just stops, but the Windows Service Control Panel says that it is still running, check your version of VT Collect is 7.18 or higher. If not download the latest version from the web site (contact us for the URL, user name and password to do so). In c:\videoturnstile\setups\ there is a batch file called VTserviceRestart.bat. Use Windows Task Scheduler to run this batch file once per day at a time when you are not normally collecting data. This will stop and restart the service every day.
16. The message "Error reading settings - attempting to restore defaults" has appeared
  • You are running VT Setup and can contact the Logger, but when you try to read from the VT you get the above message. This happens because it is possible for a VT to get a new address but to be incorrectly programmed with new settings, typically because more than one unit is being programmed by mistake.
  • Ensure your version of VT Setup is 7.16 or higher, or download the latest version from the web site (contact us for the URL, user name and password to do so)
  • On getting the error message the program will attempt to restore the settings to a VT with the current address and if this fails can try address 16, which is the default address for mis-programmed VT units.
Another Problem?
If your problem isn't addressed here, first make sure that your copy of the Video Turnstile User Manual is up-to-date. You can download the latest edition from our Manual Update page. If your problem isn't covered in the Manual then please fill in the form below.

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