Listbox on MIO DMS Pinnacle - get a button event from it?

fogled@mizzou

I can't figure out how to get a button push in a dynamic listbox on a DMS to return any kind of button_event back to the controller. I'm getting the dynamic list loaded into the panel OK, and I'm specifying a "Channel" field in that list, but button pushes don't show up in the NetLinx device notifications.

When I enable Netlinx Device Notifications, I don't see any kind of button push from the dvTP_AB. How do I get it to send that Channel number (3rd column in the list definition) to the controller?

Code snippets below...

DEFINE_DEVICE
dvTP_AB = 10003:1:0

DEFINE_CALL 'tpsetup' () { 
  SEND_COMMAND dvTP_AB,"'^LDD-1'"
  SEND_COMMAND dvTP_AB,"'^LDN-1,1,3,eventselector'"
  SEND_COMMAND dvTP_AB,"'^LDT-1,1,0,0,3'"
  SEND_COMMAND dvTP_AB,"'^LDA-1,0,1,Setup 1,21'"
  SEND_COMMAND dvTP_AB,"'^LDA-1,0,2,Setup 2,22'"
  SEND_COMMAND dvTP_AB,"'^LDA-1,0,3,Setup 4,24'"
  SEND_COMMAND dvTP_AB,"'^LDA-1,0,4,Setup 7,27'"
  SEND_COMMAND dvTP_AB,"'^LVC-1,2,1,3'"
  SEND_COMMAND dvTP_AB,"'^LVU-1'" 
}

DEFINE_EVENT
data_event[dvTP_AB] { 
  online: { 
    send_command data.device,"'PAGE-Selection'"
    call tpsetup ()
} 
string: 
{
  send_string debug,"'Panel AB Sez: "',data.text"
}

button_event[dvTP_AB,21] 
button_event[dvTP_AB,22] 
button_event[dvTP_AB,23] 
button_event[dvTP_AB,24] 
button_event[dvTP_AB,25] 
button_event[dvTP_AB,26] 
button_event[dvTP_AB,27] 
button_event[dvTP_AB,28] 
button_event[dvTP_AB,29] 
{
  send_string debug,"'AB Panel Button Event: "',itoa(button.input.channel)"
}