Although the ZRT offers state-of-the-art performance, it has been designed with cost in mind. It offers straightforward modem capability without any unnecessary  or expensive extras.

The ZRT has been specifically designed around low current circuitry to allow use on remote sites without limited power.

The receiver is a very low current, double conversion superheterodyne with an active balanced mixer for very good intermodulation performance. Careful attention to spurious response, adjacent channel and blocking performance makes the product ideal for crowded telemetry radio channels.

All key operating parameters can be easily set using the supplied configuration software.

In addition to the inherent low power consumption of the design, the ZRT also incorporates a number of sleep modes which reduce the consumption to below 100µA.  Sleep mode can be controlled either by an external input or by an internal timing circuit.

Up to 80 channels to be pre-programmed into the ZRT and rapidly selected using the two front panel rotary switches.  The switches can be locked-out under software control and the radio programmed for a single frequency by the user if preferred.

The transmit power can be accurately set in 1dB steps under software control.

The serial interface includes all handshaking signals and conforms to the standard pin-out arrangement for RS232 connections.  This allows off-the-shelf cable assemblies to be used for connection to external equipment.  The modem can also be set for “Key-on-Data” operation and then only requires the Tx Data, Rx Data and Ground pins to be connected.

The user can select the over-air data rate independently of the rate on the serial interface.  An internal buffer copes with situations where the rates are different. Over-air rates between 150bps and 9,600bps are possible.

For old or non tolerant protocols, where the presence of a mute (squelch) tail may cause a problem at the end of a message, a simple packetisation option can be enabled using the configuration software.

The transmitter within the ZRT has a time-out timer which allows the maximum continuous transmission time to be set in order to prevent channel blocking due to a to fault in any connected equipment.