Crown IQSMX-6 6.3The Mixer/Multiplexer as a 1-LoopIQ Interface, Crown Local Net IQ-SMX-6only

AMB-5 /SMX-6IQ Mixer/Multiplexer

6.3The 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.**

*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.

CLN Interface	CLN Interface	CLN Interface
RS232	RS232	RS232

Figure 6.16 A Crown Local Net RS232 Serial Loop

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.

Figure 6.17 Crown Local Net Wiring

Page 28 IQ–AMB-5 / IQ–SMX-6 Reference Manual