Product Details:
The Selective Call Unit is an encoder / decoder designed for operation with radio communication networks. The unit encodes signals for paging individual stations or the entire network. The unit also decodes incoming signals to determine if the station is being called. The unit is also equipped to alert the operator to incoming calls, display the calling station's ID code, acknowledge the receipt of a valid code and provide the calling station a verification code. The unit can interface to land line or radio links.

This unit may be used for protected access to remote control receivers for repeaters or remote base stations. It can also be used as a selection control encoder for multiple receive locations.

Up to 256 Unit IDs may be programmed. The Sending Unit ID is preset on an internal circuit board. The Called Unit ID is selected by front panel thumbwheel switches.  Upon receipt of a valid call the ID of the calling unit is displayed on the front panel LED display, an internal buzzer sounds, a dry contact closure is available on the rear panel and the "CALL" LED lights. At this point an automatic response confirming receipt of the call may be sent out on the control link to the originating station. An internal jumper may be set so that the response is only sent when the "CALL BACK" button on the front panel is manually pushed. The units are designed to be reset after a call only by use of the manual front panel push-button switch. The reset is accomplished by momentarily grounding the reset line.

The dry contact closure may be set by internal jumper to "timed" or latch mode. In latch mode an external 'reset' pulse would be necessary to release the relay. This could be implemented by a special code sent to the repeater controller that causes the 'reset' pulse to be sent to the Selcal unit, thereby un-latching the relay. An alternative is to use the timed mode of the relay to start a timer which allows audio (with control tones) to get to the repeater controller and upon timeout the line is disconnected and the reset code is sent back to the selcal.

Selcal units operate from 120 / 230 vac or 12 vdc at 1 amp. Requires HP style AC cord with 3 round pins or coaxial connector for DC operation. Internal switch and jumpers select input power requirements.

Size 5-1/2" x 19" x 14" deep (rack mount). Rack mount frame may be removed to make unit 5-1/2" x 8 1/2" x 14". Internal plug-in cards are accessed by releasing the screw latch and swinging open the hinged, front panel door.

Complete manual for the unit is included with each order.