Rane HAL System Design Guide - Page 32

HAL SYSTEM DESIGN GUIDE The Locate LED flashes green when you place this HAL device in Locate Mode (via the Halogen software). The purpose of this Locate functionality is for verification, when working in the software, of the physical device you are configuring or viewing. The Power LED lights when the HAL hardware is powered on. Remote Audio Devices The primary purpose of a Remote Audio Device (RAD) is to amplify, digitize, and transmit a digital audio signal via shielded CAT 5e cable to a HAL host device. RADs can also receive a digital signal from the HAL and then convert it to analog before sending it to its attached audio equipment. RADs are capable of transmitting and receiving up to four channels of digital audio (two in each direction). To better fit your needs, however, Rane offers various RAD models. Most RAD models are designed to fit in a standard U.S. two, three, or four gang switchbox. The HAL System offers a variety of RAD models, each of which serves a unique purpose. For example, a RAD1 contains two microphone input channels. When you design an audio system, you choose the RAD models that are appropriate for your application. You must then provide configuration information to HAL so that it knows which RAD models to expect on each port and what information to send to each RAD. For more information, see "Available RAD Models" in the Halogen Help System. You can also read about the available RAD models on the Rane website. How the shielded CAT 5e Cabling is Utilized The shielded CAT 5e cable that connects the RAD to HAL also provides power to the RAD as well as a path for data communications. Data communications makes it possible to control the RAD's configuration settings, view status information, and update a RAD's firmware - all from the host HAL device. The following picture illustrates how the four twisted pairs within the shielded CAT 5e cable are utilized. l The orange pair is reserved for data communications between the RAD and HAL. Data communications is needed for such things as sending configuration information from HAL to the RAD, sending firmware updates from HAL to the RAD, and sending status information from the RAD to HAL. NOTE: Configuration information for a specific RAD (for example, LED intensity, microphone sensitivity, and RAD and channel names) is stored in the HAL device, not in the RAD. This makes it easy to swap in a new RAD, if necessary, without losing configuration data. l The green and blue pairs carry two channels each of balanced, differential, digital audio. Tx refers to audio that the RAD sends to the HAL. Rx refers to audio that the RAD receives from HAL. l The brown pair provides 24 VDC power and ground for the RAD. This is (obviously) the wire you should check if it appears a RAD is not receiving power. NOTE: Digital Remotes (discussed on page 47) use only the orange pair (for data communications) and the brown pair (for power). 26