[CA] [CA11] Low voltage to itc5 for wind speed

[Chuck - Raymarine - Moderator]

Terry,

Q1. I found a 'T' with white wire to the EV-1 and the 2nd backbone end plug..
A1. As you have now located where the questioned Backbone Cable leads, you may want to consider updating your drawing for future reference to include this T-Piece and to indicate where the Termination Plugs have been installed. Based upon your description , the backbone appears to be properly terminated and appears to been properly powered.

As indicated within the FAQ addressing how to test a masthead transducer,

- Red to shield of the iTC-5 or wind instrument should read 8V DC steady. This is the masthead power supply, coming from the ST50/ST60/i60 Wind instrument or iTC-5. If I understand your initial post, this is the value which you measured 8.4VDC and this would then be considered normal. While the iTC-5 will receive 12VDC from the backbone, only 8.4VDC will be provided across its red to shield pins

- Blue to Shield should read anywhere between 2V and 5.8V DC ... you did not indicate measurement.

- Green to Shield should read anywhere between 2V and 5.8V DC ... you did not indicate measurement.

Blue and green are a sine-cosine wind angle pair. The wind angle is what instruments use to detect the presence of the transducer, so if you have an incorrect voltage here you will often see no wind data at all.

- Yellow to shield should read between 0V and 5V DC (the exact voltage depends on the instrument: 3.2V is typical for ITC5, more like 5V on ST60.) ... you did not indicate measurement.

Should you have unplugged the Backbone Cable from the iTC-5 and measured the power from the Backbone Cable's power pins and found that the measured voltage is less than that of the circuity which is feeding power to the backbone (recommend testing at the backbone's Power Cable), then one or more of the devices which have been connected to the backbone is faulty and is loading down the backbone. The problematic device would be identify by disconnecting device one by one and then measuring the power present within the Backbone Cable.

Q2. Still confuse about seatalk hs wiring. Currently there are 4 connections, one is 12v power, one is DSM300, one is radar and the last goes to the e125 mfd. Both the radar and DSM are working . Where is the wiring problem?
Q2. As indicated earlier, only the MFD, DSM, and radome should be interfaced to the SeaTalkhs Network switch. Power is provided to the SeaTalkhs Network Switch via its power terminals. As your MFD is communicating with the DSM and radome, no further changes would be required after ensuring that only these devices have been interfaced to the SeaTalkhs Network Switch.