Rudder Sensor - Displaying Impossible Values on TZ Touch 2

[personalt]

Have a TZTouch 2 display connected to a Simrad RF25 rudder sensor, boat came with both devices. Rudder degree value properly displays at zero on Tztouch when centered. But two turns to port displays as 10 degrees and two turns to starboard displays as 50 degrees. But looking at the rudder and the sensor both the ram/rudder moved the same distance in each direction.

I posted about this on a few forums and keep getting responses about calibration and auto pilot but I dont have auto pilot and I think people are jumping ahead.

My question is simple, if you go to the NEMA 2000 sensor page under setup is the TZTouch modifying those values in any way or is that just publishing the messages on the bus? I think the sen. I kind of thought that the Nema screen under setup was just printing everything that was available and not messing with the data at all. Is that right? Or if there really a calibration on the rudder sensor somewhere in the unit. And by calibration I mean how the unit displays degrees of change not what it does with that data.

 

[Quitsa]

Most rudder sensors are "dumb" and meant for use with autopilots and connect to the autopilot's processor unit, which typically then also translates the resistance values to degrees and transmits the NMEA 2000 PGN for rudder angle.

You have a "smart" sensor that incorporates the processor and creates the PGN directly.

As far as I know and have experienced, the TZT 2/3 do not change the values received from sensors except for a handful available on the calibration menu such as heading and speed through the water. This would suggest that your RF25 is outputting PGNs with the incorrect rudder angle and the TZT2 is just displaying that incorrect data.

When you go to the "Data Source" menu, you should see the rudder position sensor and then the current rudder angle value. Try looking at that screen while you turn the wheel and see how the value changes.

The only other thing I can think of would be to hook up another device that can read the rudder angle PGN and display it such as an instrument display and see if you get the same incorrect readings.

Have you tried contacting Simrad customer support (far inferior to Furuno but they do have it) and posing the question to them? It is not impossible that there is a proprietary calibration regimen that can only be done with a Simrad display. I have Garmin GFL-10 NMEA 2000 tank level senders for example and they can only be calibrated by a Garmin device.

 

[personalt]

Yes this one is a smart sensor, outputs NEMA traffic. On what I think is the same data source menu you are talking about (Under setup / NEMA 2000 / showing all the data for all sensors) I see the same wrong values. By wrong I mean it moves/updates twice as far going to port vs starboard.

Simrad is the next call tomorrow. Thanks