When using a Push-To-Talk switch (PTT) on panels, the most common configuration is to choose Activate All Pre-Selected Talk Keys.
This changes how the panel behaves - latching a key no longer turns on the microphone, instead it needs an additional trigger to turn on the microphone and route audio - the PTT input. Holding down on the panel key will temporarily override this behavior, allowing a momentary talk without the PTT.
To have more control over the behavior, the Logic feature Panel Mic Mute can be used. This turns off the microphone, usually to act as a cough switch, or similar but we can also use it to prevent the microphone being turned on except when the PTT is active.
First, create a control in the Controls screen. Each panel will need its own.
Then go to Panels and make this control fire when the PTT or Logic Input is active:
Finally, we need to set up the Logic Diagram. Go to Logic, create a new Diagram, click Edit Logic and then make the following:
When the Logic input is off, the panel microphone will always be muted, even if keys are latched.