FI-70 displays two different depths side by side

[JordanBigel]

How is this possible? This image shows two FI-70 instruments mounted side by side. The left one is configured to show the depth over time chart in blue (the boat is motionless) and the right side shows a page of various data, one of which is Depth (center/right).

http://www.bigel.net/download/FI-70-sid ... -depth.JPG

But they don't show the same depth - the instrument on the left shows 12.1 ft and the instrument on the right says the depth is 10.1 ft. (which is exactly 2ft apart, I am sure that is significant somehow).

Now, to make it more interesting, I also have a TZTouch2 in the system which I believe is supposed to be the master for all the FI-70s with respect to calibration, units, etc. However, this does not seem to be the case. It works if I set the units on the TZT2 (say, between Meters and Feet - the FI-70 correctly changes to those units). But the depth is different, and its different from both of the FI-70 screens I described above.

For example, on the TZT2 my external transducer draft is set to 2ft - the depth readout (DPT) on the TZT2 seems to show the transducer draft added to the depth shown on the FI-70 (chart page). So, for example, if the FI-70 chart page shows 12.1 ft, and the TZT2 transducer depth is set to 2 ft, then the TZT2 will show 14.1 ft of depth. The second FI-70 with the plain depth number still shows 10.1 ft. So, I basically have 3 different depth readings depending where I look... Changing the transducer draft on the TZT2 has NO effect on the FI-70 displays. Neither did it effect the depth displayed, of the delta (difference) between the chart page on the left instrument and the data page on the right instrument.

Will the real depth please stand up?

Is this normal?

Thanks,
Jordan.

 

[JordanBigel]

Ok, so I found that the depth calibration was different on the two FI-70s. I set them bot to 2ft, which is the depth of the transducer below the waterline. But on the TZT2, the Transducer Draft ADDs to the depth shown on the FI-70, even if I set it to 0ft it still shows the depth reading is 2ft more than on the FI-70. I probably should have posted this in the TZT forum. Ultimately, I set the TZT to readout "Below Keel" instead of Waterline, and then set the transducer depth to 2.5' (the keel depth is 5.5') - the end result is the TZT now shows the same depth as the FI-70s. Is it the right depth? I will have to get out a lead line tomorrow and actually measure the depth here in my slip and then make adjustments to both the FI-70s (all of them?) and the TZT2. My big question remains, why isn't all this synchronized by the TZT2? Why do I have to calibrate the depth on each FI-70? Even after I drop the lead line and find out the actual depth, why do I have to adjust each FI-70 (I have 5 in total, 2 at nav desk, 3 in cockpit).

 

[Johnny Electron]

Have you seen para. 4.1.1 of the FI70 manual? It talks about how to share setting data between your FI70s and the TZT2.

 

[JordanBigel]

Have you seen para. 4.1.1 of the FI70 manual? It talks about how to share setting data between your FI70s and the TZT2

I’ve set the FI-70s to Sharing = “Sub” and 2 are in group "A" (nav desk) and 2 are in group "B" (cockpit).

Also, I want to stress that other settings which I have configured on the TZT2 do carry over to the FI-70s (for example, if I change the setting on the TZT2 from Feet to Meters, I can see the change on the FI-70s).

However, I also noticed this in section 4.1.1 which you mentioned above - it says the “Master” option should not be available, and it is. There are 3 options Stand Alone, Sub and Master and I see all 3 of them on the FI-70s even though section 4.4.1 says this:

[Master]  Where a TZtouch2 unit is in the same network, the TZtouch2 unit is automatically assigned as the [Master] and this option is not available

So, let me try to explain the issue again from the top more clearly and with better organization.

As I said above, I have a TZT2-12 and a bunch of FI-70s. All are set to Sub. Two are in Group A and two in Group B. All of them exhibit the same issue.

To start, I checked both the FI-70 and the TZT2 and found these settings and values displayed.

FI-70s
- offset (depth) = 0
- depth = 12.7 ft

TZT2
- depth display: under sea level
- external transducer depth: 3.5’. *depth of the transducer below the waterline
- keel draf: 5.5ft *depth of the bottom of the keel
- depth displayed = 16.5 ft

Next, I went outside and dropped a lead line off the side, close to where the transducer is. The depth measured 15’ 3” as best as I could tell.

So, with this as a baseline of information, Since I am fairly confident about the keel draft setting (depth below keel) I changed the External Transducer Depth from 3.5’ to 2.5’ and that changed the TZT2 display to be 1 foot less, as expected. At this point, I am seeing the depth on the TZT2 as 15.3 ft which is within an inch or so of what I measured, so great! Awesome.

However, the FI-70s still say 12.7’ - no change at all. My only recourse (which I admit, is not the end of the world) is to set the offset on the FI-70 directly (in this case, I guess I would set it to 2.5’ to get it to read 15.3 instead of 12.7). I didn’t mention, I have 5 FI-70s, so, kind of a pain, but, sounds like a bug to me.

 

[Johnny Electron]

We tested and found that TZT2 v6.23 has a problem with syncing the values correctly with the FI70. 6.21 or 6.26 didn't have this issue. I recommend you upgrade your TZT2 to the newest software (v6.26). If you are going to sync the settings, you will also need to ensure that you don't place offset values into the FI70. Upgrading the software should fix the issue for you.

 

[JordanBigel]

Thanks.
Sounds like a good time to learn how to upgrade...