Have one PDM control other PDM's at the same time

Updated by Bryan Jones


This document applies to all 25-Seven PDM units. This includes;

  • Generation 1 PDM units - Module B599 and LOWER.
  • Generation 2 PDM units - Module B600 and HIGHER.
  • PDM II units - new Generation PDM - has PDM II printed on the front of the unit.
  • PDMx - Virtualized PDM units that run in a Docker container.
Although the screen may look slightly different between versions the functionality is the same. An Original PDM can be used with a more modern PDM II without issue.


This often used where a station might have some programming that is syndicated, or any any situation where two or more PDM units are used and you want to mimic the controls from a "leader" PDM to the "folower" PDMs

This document is going to be using the Livewire GPIO ports. Note that For Gen 1 and Gen 2 PDM the Livewire ports are not available when the physical IO is used. However the principles discussed here work the same even if wired GPIO is used.
For PDM II and PDMx the Livewire GPIO is available all the time. That is to say you can use the LIvewire GPIO ports even if you are not using Livewire for anything else.

Step by step

Part 1: Configure Livewire GPIO on the Leader PDM

This is the PDM that you want to control your other PDM's from

  1. Log into the web gui
  2. Go to the Configuration tab
  3. Under "Livewire GPIO" Ensure that Livewire GPIO is enabled
  4. Find an unused GPIO port. Note the Port # you are using. In this example I am using Port 2
  5. Set the Outputs as follows: Pin 1 = BuildTrig, Pin 2 = Exiting, Pin 3 = DumpTrig
  1. Click the Apply button

Part 2: Configure Livewire GPIO on the Follower PDM(s)

  1. Log into the web gui
  2. Go the Configuration tab
  3. Under "Livewire GPIO" Ensure that Livewire GPIO is enabled
  4. Find an unused GPIO port.
  5. Set the Inputs as follows: Pin 1 = Build, Pin 2 = Exit, Pin 3 = Dump
  6. Set the Port Address in this syntax: IP_OF_THE_LEADER_PDM/GPIO_PORT_OF_LEADER_PDM
    In this example: My leader PDM has an IP address of From Part 1, Step 3, we are using GPIO Port # 2 on the leader PDM Which means that I want to set the Port Address of my Follower PDM to be:
    The follower PDM will connect to the leader PDM, on the desired GPIO Port. This is how the Follower will receive the commands from the Leader PDM

  1. Click the Apply button

Repeat Part 2 the same way for any additional PDM's that need to Follower the Leader PDM. You can have many PDM followers connected to the PDM leader for synchronous control of the three functions

Try it out

With both Leader and Follower PDM's, NOT in bypass, and with an empty delay buffer. Press the Build button on the leader PDM. The Follower PDM should also start to build. Same goes for Exit and Dump.

Please note. This is one way control. If someone pressed Dump on the follower PDM, the Leader PDM will not react. Only the Leader PDM will control the Followers.

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