Question:  I’d like to create a control button that can “kill” a latched button on another panel. 
Example:  “Panel  5” has latched a control button that fires a GPO and kills program audio.  I’d like an operator at another panel to be able to press a “remote Kill” button and turn OFF “Panel 5” and any other panel that has engaged that button.  I imagine this would be similar to a remote mic kill function, but I can’t figure this out.
Answer:  Yes, it is possible to create a relay kill button using a control label triggered by a Logic Maestro logic file. 
First in EHX create the following Control Labels:

• Relay 1 and attach frame relay 1 to this control (declare this control latch disable)
  
• Relay 1 Kill (no attachment and declare this control latch disable)
  
• Relay 1 activation and attach frame relay 1 to this control
  

1.  Open Logic Maestro, click on "NEW"
2.  Select Logic Diagram, name the logic diagram and give it a descriptive name, then click on "OK"
3.  Click on "Edit Logic"  to open the work palette screen for the new diagram
4.  From the Module Library drag in the following elements: 

• One Control I/P
• One Control O/P
• One Panel Control

5.  From Logic Elements drag in a Latch6.  Connect the Control I/P to the Latch "T" by dragging the mouse pointer from the Control I/P to the Latch "T"7.  Connect the Control I/P to the Latch "Q" using the mouse pointer8.  Connect the Panel Control to the Latch "Q"

9.    On the Control I/P attach relay 1 control with relay 1 attached and 2nd control labeled relay 1 kill from the Configuration Elements column
10.  On the Control O/P attach relay 1 activation control with relay 1 attached11.  On the Panel Control set the following parameters:

• Green or Red indication (this is for the tally indication on the Relay 1 control key on the panel(s)
• Indication 2 Hz (tally blink rate)
• Add Panel (place all panels that will have the Relay 1 and Relay 1 kill control keys on them)
• Add Label (Relay 1 control label, this will receive the tally indication)

12.  Click on "OK" to save the logic diagram13.  Enable the logic diagram with a checkmark. 
14.  Apply the configuration to the frame. 
15.  Place the Relay 1 and Relay kill 1 control labels on the desired panels as talk keys16.  Apply the configuration to the frame
When the Relay 1 label is activated the frame 1 relay is now activated and the Relay 1 control label will blink red or green depending on the color selected in step 11.  When the Relay kill 1 key is activated the relay will be deactivated. 

See below the logic diagram with connections and attachments: