CAS is a multiprocessor system, that uses three combined computers, the host, the slave CPU and the console interface boards. All these units are installed in the main frame, that has all necessary connections for the monitor, the keyboard, the time code and the console interface.

The host is an industrial PC. The PC handles the screen, the mass storage devices and the keyboards. It is mounted in a 3U high cassette module that contains the entire computer with harddrive, floppy, graphic board and all necessary connectors.

The Slave CPU stores and processes the mix data in an 8MB static RAM bank and handles the data transfer from and to the faders. The static RAM holds the mix data until it is expressly deleted. Power failure does not delete your mix. The slave CPU interacts with to host that displays the fader data, forwards commands from the keyboards and saves and loads the mix data. The Time Code controller is also part of the slave CPU. The picture shows this part of the main frame with removed cover sheets. (hi-res view here).

The graphic shows the connectors of the PC section. (hi-res view here)

The Console Interface Boards are hardware processors. Every interface board handles 16 faders. It contains the AD and DA converters, the analog I/O section and a dual ported RAM section that maintains problem free, fast, communication between the slave cpu and the interface boards. The internal processor scans the 16 faders permanentely. Every fader section is updated 400 times per second. This principle makes sure, that there is no additional delay. When you move the fader the data in the dual ported RAM is updated within 2.5 ms. Data that comes from the mix memory is transfered to the VCA's within the same time. Up to 16 interface boards can be installed in one CAS system. Several different Console Interface Boards are available. While all versions are compatible with the CAS slave CPU bus, the fader interface of the different versions makes it possible to use the system with every adt-audio console that was delivered in the last 20 years. Interface boards of different types can be mixed in one CAS system without problems.

A basic system includes the main frame with the host computer, the automation controller slave CPU and at least one console interface board for 16 faders. The CAS frame can be mounted directly below the console. It contains all the necessary components and can be used with systems up to 128 channel. An additional frame is necessary if the number of channels exceeds 128. Rack-mount versions are available. These versions use 3U high frames for the interface boards and an additional 3U high frame for the computer section. A 3U high frame can hold up to 8 interface boards for a total of 128 faders. Systems with more faders require a second frame.

The picture shows the main frame version that is mounted directly below the console frame with 6 interface boards for 96 faders as it is used for a Series D console.
Open high resolution view of the main frame in new window here.