6.3 The Mixer/Multiplexer as a 1-Loop IQ; 6.4 Crown Local Net (IQ–SMX-6 only); 6.4.1 Wiring the Crown Local Net- Page 28

Page 28

IQ–AMB-5 / IQ–SMX-6

 Reference Manual

AMB-5 / SMX-6

  IQ Mixer/Multiplexer

6.3  The Mixer/Multiplexer as a 1-Loop IQ
Interface

The mixer/multiplexer can serve a an IQ interface
between a host computer and a single Crown Bus
loop for other IQ–AMB-5/IQ–SMX-6 units only. This
can eliminate the need for an external IQ Interface
(

IQ-INTII) in a small system. The mixer/multiplexer

connects directly to the host computer via the DB9
serial connector. Switches accessed through the
side of the chassis are used to select the parity and
baud rate. See Section 3.2 for specific instructions
on wiring and switch settings.

While 250 IQ components of each type can be con-
trolled on a single Crown Bus loop, it is recom-
mended that no more than 20 units be connected to
an mixer/multiplexer. This is because of the tremen-
dous timing demands on their microprocessors.
More than 20 IQ components may cause timing
problems.

6.4 Crown Local Net (IQ–SMX-6 only)

Crown Local Net (CLN) is available only for an IQ–
SMX-6. It enables multiple IQ–SMX-6s to be inter-
connected via a CLN. This is an RS232
communication loop designed for local communica-
tion between IQ components apart from the Crown
Bus. IQ–SMX-6s can use this option to communi-
cate the total number of open mics in the system as
well as their individual ducking priorities. In this way,
one IQ–SMX-6 will know how many mics are being
used by other IQ–SMX-6s and can take appropriate
action to prevent feedback or implement priority
switching (ducking) of mics.*

6.4.1 Wiring the Crown Local Net

A Crown Local Net is a serial loop (Figure 6.16).
With two exceptions, a Crown Local Net loop is
wired the same as standard RS232 wiring, except
the Crown Local Net does not use handshaking
therefore pins 7 and 8 (RTS/CTS) are not used.

Figure 6.17 shows the wiring for a 3-unit Crown
Local Net. If more units are desired, simply add
another unit and follow the same pattern for wiring.**

Important: The Crown Local Net must make a
complete loop. If the last unit in a group is not
connected to the first unit, the system will not
function.

Important: The Crown Local Net depends on
proper IQ address assignments, even if the sys-
tem will not be installed with a Crown Bus loop.
Each unit in a Crown Local Net must have a
different IQ address.

See Section 3.2 for details.

As more diverse IQ communications

  are needed,

the Crown Local Net will be available to move infor-
mation directly between IQ components without af-
fecting the performance of a host computer.

CLN Interface 

RS232

CLN Interface 

RS232

CLN Interface 

RS232

*  Because Loop IQ Interface and CLN use the same DB9 connector, they
cannot be used at the same time. This means that IQ–SMX-6s to be used in
a CLN will need to be connected to a Crown Bus via an external IQ interface
for setup.

** Pin 5 should not be used as a ground if the units are already properly
grounded. The wire used for RS232 communication is usually unsuitable for
use as a ground.

Figure 6.16 A Crown Local Net RS232 Serial Loop

Figure 6.17 Crown Local Net Wiring