The XDS Analog Line Interface boards address the inherent negative voltage supply limitations of most PCs. Practically all analog telephone interface boards require a negative power supply of either -5V or -12V. PCs can typically provide only 0.5 Amp or less of either of these voltages. In order to avoid exceeding this limit when multiple boards are used, a local power supply located on each XDS board provides the required negative voltage. Because of this, port capacity is not limited, and you can build your application to the size you need utilizing standard PCs.

The Line Interface boards utilize on-board intelligence to handle line control, supervisory and tone signal functions with minimal host intervention, so that developers may use their valuable PC resources for their application, not to control analog line boards.

The Line Interface boards are smart boards that do not need associated voice boards to function. For developers, this means easy implementation with fewer card slots. The Line Interface boards are ISA compliant. DOS, OS/2, UNIXWARE, and Windows NT drivers are available.

DID - The DID (Direct Inward Dialing) board implements RS-464 and IEEE standard DID protocols, including Wink and Immediate Start, as well as DTMF and Pulse Dialing.

The 8-port DID board is attached to phone lines where the identity of the party being called is sent along with signaling and audio. The identity consists of part of the phone number being called, and the DID port on the receiving end is equipped to recognize the identity.

The DID port supplies 48 volt battery to the phone company. It also provides battery reversal and current sensing for off-hook detection.

Station Interface - The Station Interface board functions as an interface to analog telephones.

The Station Interface is a battery feed port that supplies talk battery but is also capable of applying ring voltage and message waiting voltage to the line. All normal line status and control functions are provided. Battery is applied at all times and current detection is always available.

The 8-port Station Interface board has the ability to light standard message waiting indicators.

Loop Start - The Loop Start board is connected to a loop line from the telephone company to receive incoming and place outgoing calls.

The 8-port Loop Start board provides all normal line status monitoring. It furnishes battery sink and current detection when off-hook. When on-hook, ring detection is available.

Ground Start - The 8-port Ground Start board is capable of ground start operation, in addition to providing all the functions of a Loop Start line.