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[CA] [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - Printable Version

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[CA11] EV-1 Cycles 360 Degrees (Even While Docked) - dlane1181 - 11-23-19 04:13 PM

Hello Forum Members and Moderator.

While trying to recalibrate our EV-1 compass we were unable to complete the Align to GPS steps. The display showed "Task Failed - inconsistent values." Once back at the dock, I noticed our COG display was cycling 360 degrees around the compass. If it will go through, I've attached a short video clip showing the COG display (taken with our vessel tied to the dock).

Our system seems to be working well otherwise.

Please assist with troubleshooting.

Thank you.


RE: [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - Chuck - Raymarine - Moderator - 11-25-19 01:19 PM

Welcome to the Raymarine Forum dlane1181,

Please note that COG data is derived from GPS data. A vessel has no valid COG when it is stationary (ex. tied to a dock). Accordingly, any attempts to align to COG after the vessel has completed the cruise to determine the deviation sensed by the autopilot must be performed while the vessel is underway and making way on a steady heading. Should the problem occur under such conditions, then please indicate the make/model of chartplotter/MFD is installed onboard? If the chartplotter/MFD/system has been interfaced to an external GPS sensor, please specify the make/model of GPS sensor which has been installed. Finally, when the problem described is observed, please specify the HDOP value reported within the GPS status dialog of the chartplotter/MFD.


RE: [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - dlane1181 - 12-16-19 09:56 AM

Dear Sir,
Sorry for my delayed response. We are now back aboard our vessel.

- To clarify, when calibrating the EV-1 and autopilot while underway, the GPS failed to align to the GPS. Dockside checks were successfully completed. The underway checks and other steps were also done successfully, except for GPS alignment, which simply entails maintaining a steady course for a few minutes, which we did. However, we received the following message on the p70 display, "Task Fail - Inconsistent values." Later, when back at the dock, we observed the COG cycling 360 degrees.

Should the problem occur under such conditions, then please indicate the make/model of chartplotter/MFD is installed onboard?
- We have an Axiom 9, selected as data master, at the navigation station, and an Axiom 12 at the helm. We observe the COG cycling 360 degrees continuously, even when docked and with no way on. It also continues to cycle when I change the data master from the Axiom 9 to the Axiom 12.

If the chartplotter/MFD/system has been interfaced to an external GPS sensor, please specify the make/model of GPS sensor which has been installed.
- No external GPS sensor has been installed or is being used.

Finally, when the problem described is observed, please specify the HDOP value reported within the GPS status dialog of the chartplotter/MFD.
- HDOP = 1.5 as read on 16 December 2019, at 16:36 UTC.

Thank you for your assistance with troubleshooting this problem.
DAL


RE: [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - Chuck - Raymarine - Moderator - 12-16-19 10:40 AM

DAL,

The GPS HDOP is high for whichever MFD's GPS receiver has been selected as the system's GPS data source. High HDOP will cause relatively large random position errors and accordingly result in detected vessel movement (which in turn will produce COG) when the vessel is stationary. In system installations which do not afford the MFD functioning as the system's GPS data source an unobstructed view of the skies overhead, an external GPS sensor (ex. Raystar 150 GPS Sensor, etc.) may be required ... as appears to be the case within this system. The external GPS sensor would be installed in a location affording it an unobstructed view of the skies overhead. Should the MFD functioning as the system's GPS data source be installed in a location affording it an unobstructed view of the skies overhead, then it would appear that the MFD's internal GPS receiver is not functioning properly and should be sent to Raymarine’s Product Repair Center to be bench checked / serviced.


RE: [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - dlane1181 - 12-17-19 04:11 AM

Thank you for the insightful commentary. Both of our Axiom MFDs are mounted without unobstructed views of the skies overhead. However, although the reported HDOP is high (presently 1.2, down from 1.5 a day ago), we already have an external GPS sensor mounted atop the main cabin with an unobstructed view of the skies overhead. (It is not a Raystar 150, and I cannot tell what make or model it is.)
Until recently, though, our nav suite worked as advertised and we had no issues with erroneous COGs whether underway or stationary.
I suppose our GPS sensor could be failing, or we have a faulty connection between the GPS sensor and the MFD data master. Do you have any troubleshooting suggestions for determining either? I'll try and trace the line from the sensor to the MFD, weather permitting.

Here is additional information for the conversation as of 12:00 UTC, 17 December:

It's a bright, sunny day today and HDOP values have ranged from 0.7-1.3. The COG continues to cycle through 360 degrees on the MFD itself despite no way on; however, no COG is displayed (--) on the i70 instrument, whereas it was cycling on this display previously.

We traced the GPS Sensor lead from the cabin roof to our Raymarine E32158 AIS transceiver. All connections and contacts appear intact, and we noted no kinks in the coax cable connecting the two components. The AIS transceiver is integrated into our Raymarine nav suite via a Raymarine HS5 Network Switch.

Although possible, it seems unlikely that the GPS Sensor connection is faulty.

Thank you for your any additional technical troubleshooting tips you can provide.
Thank you.


RE: [CA11] EV-1 Cycles 360 Degrees (Even While Docked) - Chuck - Raymarine - Moderator - 12-17-19 10:14 AM

DAL,

Q1. It's a bright, sunny day today and HDOP values have ranged from 0.7-1.3.
A1. With modern GPS receivers, cloud cover and weather have little impact upon GPS performance. The reported HDOP remains high and may indeed be associated with the reported issue. Please click here to view a FAQ addressing GPS accuracy and other factors which may affect it.

Q2. We traced the GPS Sensor lead from the cabin roof to our Raymarine E32158 AIS transceiver. All connections and contacts appear intact, and we noted no kinks in the coax cable connecting the two components. The AIS transceiver is integrated into our Raymarine nav suite via a Raymarine HS5 Network Switch.
A2. From the standpoint of how an AIS650 would be interfaced to the system of MFDs lacking a NMEA 0183 communications interface, the AIS650 is designed to be interfaced as a spur to the system's powered and properly terminated SeaTalkng / NMEA 2000 backbone, not to a HS5 RayNet Network Switch. The latter would be used to interface compatible devices having an Ethernet communications interface to the system.

Passive GPS antennas are designed to collect GPS satellite signals and pass them to a GPS receiver (ex. AIS650, AIS700, Axiom Pro MFDs, eS-Series MFDs, etc.). Accordingly, these GPS antennas must be directly connected to the device housing a GPS receiver. In contrast, a GPS sensor combines a GPS antenna and GPS receiver within a single package (ex. Raystar 150 GPS Sensor, etc.). While Raymarine's Class B AIS transceivers feature an internal GPS receiver which is designed to be interfaced to the supplied passive GPS antenna (as opposed to a GPS sensor), Raymarine's Class B AIS transceivers are not designed to transmit processed GPS data to the system via the Raymarine's Class B AIS transceivers's SeaTalkng / NMEA 2000 communications interface. Accordingly, the AIS650 in conjunction with its passive GPS antenna is not function as the GPS data source for the rest of the Raymarine system. Instead, the GPS receiver within one of the MFDs installed onboard would appear to be acting as the system's GPS data source.

As these MFDs have been installed in a location which does not afford them an unobstructed view of the skies overhead and higher than normal HDOP is being reported, it would be recommended that a Raystar 150 GPS Sensor added to the system. This GPS sensor should likewise be installed in a location affording it an unobstructed view of the skies overhead. After doing so, the Data Sources feature of the system's i70 MFID (preferred) or Data Master MFD should be used to manually select the Raystar 150 GPS Sensor as the system's Data Source for GPS data, Time & Date data, and for Datum data. Alternatively, should there be a belief that the internal GPS receiver within one or both of the system's MFDs is not performing properly, then these MFD may be sent to Raymarine’s Product Repair Center to be bench checked / serviced.