Hi Bruce
You're decribing my exact configuration although I built my own cable. The configuration is documented on this site if you just search for D710. Keep in mind that I found that the development version after February 2017 isn't parsing the GPS pass through from the D710. The public stable release and all development releases including February 2017 work just fine.
You have to run the D710 in APRS mode and have the radio configured to output on the serial port on the head. I think this is menu 604.
Once you have the radio configured, connect your computer and use your favourite terminal program to monitor the output. You should see something like this:
$PKWDPOS,032136,A,5206,N,10637.002,W,0,0,221213,200.00*2A
$PKWDPOS,032138,A,5206,N,10637.002,W,0,0,221213,200.00*24
$PKWDPOS,032140,A,5206,N,10637.002,W,0,0,221213,200.00*2B
$PKWDPOS,032142,A,5206,N,10637.002,W,0,0,221213,200.00*29
$PKWDPOS,032143,A,5206,N,10637.002,W,0,0,221213,200.00*28
$PKWDPOS,032145,A,5206,N,10637.002,W,0,0,221213,200.00*2E
$PKWDPOS,032148,A,5206,N,10637.002,W,0,0,221213,200.00*23
VE5AA-11>APZBNC,WIDE2-2:!0000.00N/00000.00EO000/000/A=000000/V=10.2/Ti=-127/Te=-127 *Stale*
$PKWDPOS,032150,A,5206,N,10637.002,W,0,0,221213,200.00*2A
cmd:VE5AA-11>APZBNC,WIDE2-2:T#000,144,001,001,000,000,00000000
VE5AA-11>APZBNC,WIDE2-2::VE5AA-11 :PARM.Battery,ITemp,Etemp
$PKWDPOS,032152,A,5206,N,10637.002,W,0,0,221213,200.00*28
VE5AA-11>APZBNC,WIDE2-2::VE5AA-11 :UNIT.V,degC,degC
VE5AA-11>APZBNC,WIDE2-2::VE5AA-11 :EQNS.0,0.0743,0,0,1,-128,0,1,-128,0,0,0,0,0,0
VE5AA-11>APZBNC,WIDE2-2::VE5AA-11 :BITS.11111111
$PKWDPOS,032154,A,5206,N,10637.002,W,0,0,221213,200.00*2E
$PKWDPOS,032155,A,5206,N,10637.002,W,0,0,221213,200.00*2F
Once you've confirmed the radio is outputting the right data, you can configure APRSIS32. My configuration is slightly different than the documentation shows, my configuration doesn't configure the D710 at all because it wasn't valuable to me. The down side is that I lose the ability for the laptop to transmit via the D710. Here's my D710 port configuration from Aprsis32:
<!RFPort[1]>
<RFPort Name="D710">
<Protocol>KWD710(APRS)</Protocol>
<Device>COM3:9600,N,8,1</Device>
<RfBaud>1200</RfBaud>
<OpenCmd>~!!0</OpenCmd>
<CloseCmd>~!!0</CloseCmd>
<QuietTime>0</QuietTime>
<Enabled>1</Enabled>
<XmitEnabled>0</XmitEnabled>
<ProvidesNMEA>1</ProvidesNMEA>
<RFtoISEnabled>1</RFtoISEnabled>
<IStoRFEnabled>1</IStoRFEnabled>
<MyCallNot3rd>0</MyCallNot3rd>
<NoGateME>0</NoGateME>
<BeaconingEnabled>0</BeaconingEnabled>
<BeaconPath></BeaconPath>
<BulletinObjectEnabled>0</BulletinObjectEnabled>
<DXEnabled>0</DXEnabled>
<DXPath>RFONLY</DXPath>
<MessagesEnabled>0</MessagesEnabled>
<MessagePath></MessagePath>
<TelemetryEnabled>0</TelemetryEnabled>
<TelemetryPath></TelemetryPath>
<!DigiXform>
</RFPort>
<!RFPort[1]>
73, Bruce - VE5BNC