Videotec DCT - Manual (Page 170)

10 APPENDIX B - FREE MUX/DVR PROTOCOL
10.1 Introduction
10.1.1 Description
The Free MUX/DVR protocol is an alternative to the traditional protocols and enables the DCT keyboard to
communicate with other devices (e.g. multiplexers, DVR's, personal computers etc.). With this protocol it is
possible to exploit all the intrinsic properties of the keyboard such as maps and telemetry, to create a
customised graphics environment in which the user is free to choose both the controls and the graphics.
10.1.2 How it works
When specified graphics keys are pressed, the keyboard in Free MUX/DVR mode will send particular
commands in Macro (Videotec) protocol to the device being controlled. The device must be able to interpret
the commands and associate them with specified actions or functions.
The user is completely free to choose the commands to be sent, the position of the keys inside the main menu
and in the maps, and also the associated graphics.
10.1.3 The Controls
The following tables contain a brief description of the controls that it is possible to implement; they are quoted
only in order to give an understanding of the potential of the system.
For more detailed information about the construction of each individual control, see the following document:
“FreeMuxDvr-Macro Protocol 1_7.pdf”.
Controls transmitted by the keyboard:
CONTROL DESCRIPTION
VidS This control has two parameters: the number of the receiving device (address) and the
number of the camera that is to be displayed.
Both parameters can take values between 1 and 100.
FreM This control has two parameters: the number of the function to be loaded in the device and
the number of the receiving device (address).
The first parameter can take values between 0 and 127.
The second parameter can take values between 1 and 100.
JumP This control is sent automatically whenever the graphics page is changed. It is used to
identify the page occupied by the operator.
It has just one parameter that can take on the following values:
0:
if the system is displaying the keyboard main menu;
1÷30: if the system is displaying a graphics page in the maps;
255:
if the system is displaying a page that is asking for a password.
KbOK The keyboard answers “yes” to the question asked by the device using the Kck$ control.
Controls transmitted by the device:
CONTROL DESCRIPTION
Bu+$ Activates the continuous buzzer on the keyboard.
Bu-$ Disables the buzzer on the keyboard.
Buf$ Activates an intermittent buzzer on the keyboard.
PrS$ Prints a text string on the keyboard display, corresponding to the specified coordinates.
KCk$ Checks whether a given keyboard is active/present on the line.
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