Steve,
The Furuno 1721 will accept AD-10 format (clocked serial) or NEMA183 format.
For NEMA use Data-H and Data-C, pins 1 and 2, which then go to an opto
isolator U27 and analog gate U25. AD-10 format is the only one to use pins
3 and 4, CLK-H and CLK-C. It may be time to give Furuno tech support a call.
They are very good.
Doug K7ABX

"Steve" wrote in message
...
I'm attempting connect my SiTex flux compass as a heading sensor for my
Furuno 1721 MKII.

The compass input is seperate from the NMEA 0183 input from my GPS..
Totally
different connector.. called the "Gyro Connector", however, according to
the manual it also excepts input from any Flux compass sensor with NMEA
0183
output. The exceptable data (talker/sentence) are HDM, HDG and HDT.

The connector on the Furuno radar has four (4) signal connections. DATA-H,
DATA-C and CLK-H, CLK-C.

Flux compass has NMEA 0183 output (talker/sentence HCHDM (heading), HCDOD
(course) and HCXTR (deviation). Data output connector Data Output is
SIGNAL
and RETURN.

I thought this would be a simple matter of connecting compass data SIGNAL
to radar DATA-H and compass RETURN to radar DATA-C.

Doesn't work, not getting a compass input to the radar or the radar isn't
recognizing the input when I try to select it on the setup menu..

Should I be using the CLK-H and CLK-C some how..

Or, what am I missing here??

Steve
s/v Good Intentions