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  1. #1
    Join Date
    Jan 2008
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    Loytec L-VIS BACnet Help

    Hello All,

    Purchased one of these devices for a small 2 controller project. My first attempt with the Loytec product and JCI PCG controllers. We have managed to create a decent menu structure with a pretty good navigation menu. My problem is the actual point data. When we scan the BACnet data, we get all of the points but a lot of them are broken down to read and write values. For example, cooling valve output only comes in as a write value. When the value is added to the display it appears as faded. Is there a way to get the read value so it is displayed as solid?

  2. #2
    Join Date
    Feb 2008
    Location
    Purcellville Va.
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    746
    Quote Originally Posted by mechdorn View Post
    Hello All,

    Purchased one of these devices for a small 2 controller project. My first attempt with the Loytec product and JCI PCG controllers. We have managed to create a decent menu structure with a pretty good navigation menu. My problem is the actual point data. When we scan the BACnet data, we get all of the points but a lot of them are broken down to read and write values. For example, cooling valve output only comes in as a write value. When the value is added to the display it appears as faded. Is there a way to get the read value so it is displayed as solid?
    Data that is greyed out is not reliable, meaning there is a form of communication problem.

    The L-VIS has a built in webserver where you can see all your data points and the status.
    If you are updated to the latest firmware, you can do a MSTP packet capture from the device.
    Also, there are BACnet settings and statistics also available for adjustment.

    The first step (with BACnet) is to scan and bring in your objects you want to use.
    Second, verify the communication is good by checking the objects on the web page of the device.
    Then, start putting those objects into your project.

    You can always contact the support email or tech support number for more help.

    Another thing, depending on how the point is configured in the LVIS the read value will stay greyed out until it is written to. (no default value set up?)

  3. #3
    Join Date
    Apr 2005
    Location
    Perth, Western Australia
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    110
    Another thing to consider is the data point flow.
    The Cooling Valve output needs to be a write from the JCI PPG controller, because it is writing the value to the network.
    However the Loytec needs to read the value from the network, so the cooling valve value needs to be configured as a Bacnet Read Datapoint.

    If you configure the L-Vis with "write" datapoints (they will be greyed out until you have a valid value entered), then you need to input a value on the L-Vis screen, because it thinks you want to Write to the Bacnet network.
    If you configure the L-Vis with "read" datapoints then the L-Vis will attempt to read the value from the Bacnet network, so your datapoint mapping needs to be correct, for it to show correctly.

    Took me a while to get my head around the concept, and I still make the odd mistake (actually quite a few to be honest), another thing you can do is to download the LINX User manual, which also details the Loytec Bacnet workflow, in more detail.

  4. #4
    Join Date
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    Near Philly
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    Quote Originally Posted by grgjohno View Post
    Another thing to consider is the data point flow.
    The Cooling Valve output needs to be a write from the JCI PPG controller, because it is writing the value to the network.
    However the Loytec needs to read the value from the network, so the cooling valve value needs to be configured as a Bacnet Read Datapoint.

    If you configure the L-Vis with "write" datapoints (they will be greyed out until you have a valid value entered), then you need to input a value on the L-Vis screen, because it thinks you want to Write to the Bacnet network.
    If you configure the L-Vis with "read" datapoints then the L-Vis will attempt to read the value from the Bacnet network, so your datapoint mapping needs to be correct, for it to show correctly.

    Took me a while to get my head around the concept, and I still make the odd mistake (actually quite a few to be honest), another thing you can do is to download the LINX User manual, which also details the Loytec Bacnet workflow, in more detail.
    "If you configure the L-Vis with "read" datapoints then the L-Vis will attempt to read the value from the Bacnet network, so your datapoint mapping needs to be correct, for it to show correctly." This is exactly what I'm talking about, how do I configure it for read points?

  5. #5
    Join Date
    Feb 2008
    Location
    Purcellville Va.
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    746
    Quote Originally Posted by mechdorn View Post
    "If you configure the L-Vis with "read" datapoints then the L-Vis will attempt to read the value from the Bacnet network, so your datapoint mapping needs to be correct, for it to show correctly." This is exactly what I'm talking about, how do I configure it for read points?
    If I understand you correctly.
    You may not see a read value until you write to it from the LVIS.
    Add both the read and the write value to the selected control in the lvis project.
    Name:  button control.jpg
Views: 96
Size:  18.7 KB

    You may want to set up a default value in the control (text, numeric, bar, etc...)that the device uses on start up. (after a download)

  6. #6
    Join Date
    Apr 2005
    Location
    Perth, Western Australia
    Posts
    110
    In this pic below, I have pulled in a Modbus datapoint from a Chiller, so that it can be displayed.
    Name:  datapoint sample.png
Views: 82
Size:  6.2 KB

    So set your Johnson datapoint properties that you want to display on the L-Vis to write.
    i.e AHU1.Cooling_Valve_Output_Write

    Then configure a datapoint in L-Vis to read that datapoint from the network.
    Thats really all there is to it

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