Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

Flex / PG-XL Power Limiter by Band; Node-Red

Node-Red flow to provide three ranges, High, Medium, and Low, of TX Power Limit. Uses PG-XL amp mode status and Flex Server Frequency as inputs.

Download files at:




  • Alan
    Alan Member ✭✭✭

    I added a new file to the Amp Band Limit Flow set. This new flow complements the "Amp Band Select" flow by adding a "High", "Mid", and "Low" setting for the PG-XL "Maximum Allowed Watts Out. 

    There is a separate "Setup" dashboard with "sliders" to set the maximum PG-XL Watts out for each range. 

    If the PG-XL puts out a higher value of Watts in MOX, the flow will "run-back" the Flex TX power to match the "Max PG-XL Watts" setpoint. 

    Using these flows together, you have three definable ranges for TX Maximum Setpoint and for Maximum PG-XL Watts. The flow will run the TX setpoint below the lowest value. If the Flex Setpoint is below both TX Setpoint and PG-XL Watts limits, the flow will allow the Flex TX Setpoint to control.

    Here is a screenshot of the "control panel" used to set PG-XL Max Power for each range:

    And, here is a screen-shot of my station dashboard showing the consolidated "Limiter" buttons / Indications:



  • Alan
    Alan Member ✭✭✭

    I found the power runback equation was taking too large of "bites" to runback the power if power output was greater than power setpoint. It was working reasonably well, but I wanted to make it so it did not "overrun" the solution. So, I added a "factor" to tweak the power runback adjustment for your particular situation. The runback adjustment equation now is:

    var adjust = factor * (1500 - (Math.abs(delta))) / 1500;

    Where "delta" is (Power Out) - (Power Setpoint),

    Where factor is adjustable from 0.5 to 1.0.

    The flows also allow you to enter band-specific TX Setpoint limits. The flows will prevent setting your Flex TX setpoint above the limit if the amplifier is in "operate". The TX Setpoint Limit and Power Limit can be turned on/off as desired, along with the selection of three pre-determined "High", "Mid", and "Low" setpoints.

    This is the Power Runback Control Dashboard, with the new "Runback Factor" slider:

    Alan WA9WUD

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.