Functionality; Software - Tait T2004 System Manual

3

Functionality

3.1

Software

Primary Secondary Configuration
RS485
Avoiding Data Clashes
Controlling the Speaker Path
38 Functionality
Software version
2372A510
the remote control heads.
The software allows the remote control heads to work in the same way as
standard T2000 control heads, with additional features detailed below.
The control head design is altered to allow a system of multiple heads to
function with one radio. The heads are divided into Primary and Secondary
via hardware, i.e. by linking a port bit on the head processor (Secondary =
high, Primary = low). Only one Primary is possible per system.
The serial line driver in each head feeds its output to a common serial line
back to the radio. This raises the problem of multiple devices trying to drive
one line. To overcome this, the RS485 line drivers are held in a tri-state
condition until the head generates serial data. Hardware on the circuit board
enables the driver at the appropriate time. The radio can still be programmed
from a PC via any head.
The heads share a common serial data link with the radio, so in order to
overcome data clashes at power up time, Secondary heads have a 10 second
timeout during which all user input and all serial output is stopped. After
the timeout, normal operation resumes.
Note that there is no mechanism to prevent data clashes during normal
operation; the system must rely on the probability of a clash being very
small.
Muting the speaker output of one head by another head is accomplished in
hardware by phantoming a DC control signal onto commonly connected
audio lines which link all heads in the group. This line can be either driven
or its state sensed by the head microprocessor and the audio output is
is programmed into the microprocessor on all of
T2004 Multi-Control Head System Manual
© Tait Electronics Limited May 2004