17
Manual Camera Motion
The procedure for manually moving a camera is as follows:
•
Reset motion voltages with the ‘R’ command.
•
Move the camera using ‘P’, ‘T’ “Z’ and ‘F’ commands.
The following 2 sections discuss the commands used.
Camera Control Voltages
Camera motion is controlled by four voltages corresponding to the velocity of pan, tilt,
zoom and focus which are set using the ‘P’, ‘T’ ‘Z’ and ‘F; commands respectively. (An
‘X’ and ‘Y’ commands are also available to control the trolley and dolley, if used.) Iris
control may be available depending on the control panel options and lenses. The
commands have a single numerical parameter determining the voltage to which the
output is set. The value of the parameter is in the range of 0 to 32767. A parameter
value of 16383 is the point at which no motion occurs. As the value moves away from
16383, the speed of motion increases, and the direction of motion is determined by
whether the value is greater or less than 16383 as follows:
Command
< Less than 16383
> Greater than 16383
‘P’ Pan
Right
Left
‘T’ Tilt
Down
Up
‘Z’ Zoom
In (Tele)
Out (Wide)
‘F’ Focus
Near
Far
‘X’ Televator/Trolley
Down/Right
Up/Left
‘Y’ Dolley
Right
Left
“I” Iris
Close
Open
In addition, the ‘R’ command, which has no parameters, will reset all control voltages to
the no motion value.
There are many methods for determining control voltages. For instance, a joystick can
be used and the value it outputs converted to the range 0 to 32767 for control voltages.
Another example is with buttons. Each function has two buttons, one for each direction
of motion (i.e. pan left and pan right). When a button is pressed, the camera is enabled.
Initially the control voltage for the function is set for slow movement. Then the longer
the button is held down, the faster the camera moves. If there is limited processing
ability, button control can be done with simple on/off type control where pressing a
button moves the corresponding function at a fixed speed.
