12-90-0000 UHF Transceiver & Repeater

The 12-90 is a simple to configure paging transceiver with high sensitivity receiver combined with a 60mW transmitter. It operates over the frequency range of 440-470MHz decoding and encoding 512 or 1200 baud, alphanumeric or numeric messages.

The 12-90 can be controlled via a serial interface to provide numeric, alphanumeric and tone-only encoding. This enables a user to call a pager, append a priority level (1 of 4), and add a numeric or alphanumeric message.

The unit supports multiple message queuing of up to four 80 character messages, or as many smaller messages that will fit into the memory buffer.  Full batching of serially queued and input messages ensures that messages are transmitted with minimal transmit on time.  Pre-defined input messages limited to a length of 40 characters can be configured using any serial terminal application.

Two discrete inputs are supported with different pre-programmed messages on high and/or low transition.  Provision to transmit a message more than once and variable time between transmissions are catered for.

The 12-90 supports relay control protocol to control one on board relay plus several “virtual outputs”.  Virtual outputs can be used to remotely trigger input or periodic messages and provide a mechanism to acknowledge reception of messages.  Using a virtual output, it can transmit the received signal strength of the last received message allowing receiver positioning and system health to be monitored.  It can be configured to respond with checksum information of the last received message.

Expansion of the 12-90 is possible using the 12-34 relay module and 12-32 input module, allowing any number or outputs or inputs to be supported.

An intelligent self adjusting channel busy check is used to prevent message collision or corruption, reducing the need to re-transmit messages.

The 12-90 can be used as:

• A full paging transceiver, allowing both the encoding and decoding of paging messages;
• A stand alone receiver;
• A stand alone transmitter with channel busy check function before transmissions;
• An autonomous paging store and forward repeater with duplicate message reject;
• A point-to-point raw serial link;
• A simple telemetry solution.