Show Control Case Study – Frost/Nixon at Strawberry Theatre Workshop

Frost/Nixon featured extensive use of media control systems to synchronize audio and camera/video devices. The central device in the video signal chain is the Extron 1616 AV composite matrix switcher. This device inputs five camera feeds (four fixed cameras and one mobile camera) into fourteen outputs (twelve televisions and two projectors).

As is often the case with my production designs, QLab is the main system controller. The 1616 AV accepts RS-232 control messages to switch I/O routing, recall presets, etc. Utilizing CoolTerm as an intermediate controller, QLab can automate the recall of presets in synchronization with audio cues by means of AppleScript cueing. The script cues take the following form:

-- Extron 1616 AV RS-232 control scripting via CoolTerm 
-- Frost/Nixon; Strawberry Theatre Workshop, 2018 
tell application "CoolTerm" 
set w to WindowID (0) 
if w < 0 then 
display alert "No open windows" 
return 
end if 
if Connect w then 
Write {w, "5."} -- replace the string in quotes with the preset number to be recalled. Include period. else display alert ("Not connected") 
end if 
end tell

-- Extron 1616 AV RS-232 control scripting via CoolTerm

-- Frost/Nixon; Strawberry Theatre Workshop, 2018

tell application "CoolTerm"

set w to WindowID (0)

if w < 0 then

display alert "No open windows"

return

end if

if Connect w then

Write {w, "5."} -- replace the string in quotes with the preset number to be recalled. Include period. else display alert ("Not connected")

end if

end tell

This script will control CoolTermMac, sending RS-232 messages to the Extron via a TrendNet USB to Serial (DB 9) adapter, extended over twisted pair via a Monoprice RS-232 Ethernet extender.