Jenn-Air 1892 Modem User Manual


 
Hermes Operator Note Page 4 of 32
1 INTRODUCTION
This document describes the operation of the Wood and Douglas Hermes
Radio Modem.
The Hermes modems provide a transparent data link for a wide range of
applications. The internal modem can be used with a range of Wood &
Douglas RF products to give great choice in the operating frequency and
transmit power. Two enclosure types are available to suit different
applications.
The Hermes uses 4-Level Frequency Shift Keying (FSK) technology to
achieve a RF link data rate of 19,200 baud in a 25kHz channel spacing and
9,600 baud in a 12.5kHz channel spacing.
One of the radio transceivers (the G-Max family) used inside the Hermes is
designed for harsh environments and operates over a wide temperature
range and a high vibration environment.
The standard Hermes is fitted with the SXn50 range of transceivers. This
family has products at VHF, UHF and 868MHz, with a maximum transmit
power of 500mW.