ZH17 NMEA buffer / multiplexer

The ZH17 buffer-splitter is designed to provide distribution of on or two RS422 NMEA signals to eight independent RS422 outputs

It features two modes of operation, manually selectable via jumper located on the circuit board. In one configuration, one input is fed to all eight outputs, with the second input being inactive, while the other configuration each input is fed to for outputs. Signal presence for each input can be monitored by means of two LEDs, one for each channel.

The circuit uses RS422 receivers ICI for inputs stages, which results in a dramatic improvement of input sensitivity and solves the problem of working with lower signal levels, a condition often found on board. At the same time, the use of optocoupler, and isolated DC/DC converters (power supply) provides complet galvanic isolation of all inputs and outputs from the ships power and ground.

Finally, the absence of microcontroller means that no settings for bit rate, number of start/stop bits or parity are necessary.

The circuit will operate reliably with any bit rate up to at most 115200 bps. Ideal in ECDIS installations.




Supply Voltage (nominal) 24VDC
Supply Voltage (range) 18 - 36VDC
Overvoltage Protection 45VDC
Current Consumption (idle) 60mA
Current Consumption (max) 140mA
Fuse Rating 160mA FAST
Input Sensitivity 0,3V
Input Impedance 11kΩ
Differential Output Voltage (open circuit) 5V max
Differential Output Voltage (100Ω load) 2V min
Bit Rate up to 115200bps
Operating Temperature Range -15°C to +55°C
IP Rating IP20
Compass Safe Distance 0,9m
EMC & Environmental Compliance IEC 60945:2002
Dimensions 143 x 137 x 37mm