Troubleshooting Questions
HiSeasNet Equipment Questions
HiSeasNet Policy Questions

After years of operation (and answering these questions), the following list of common questions has been assembled with a variety of answers. It is hoped that operators of HiSeasNet gear will look here first for answers or suggestions of things to try in troubleshooting scenarios. This document will be maintained to better share knowledge of all ship experiences with other operators. Please send any additional questions, commends, additions, etc. to the HiSeasNet technical staff (hiseasnet-admins@epicenter.ucsd.edu).

Troubleshooting Questions

Questions in this section focus on troubleshooting situations or questions about gear that may not be functioning properly. There may be links back to the equipment section (the section called “HiSeasNet Equipment Questions”) when discussing how the gear should be operated.

I have 4 green lights showing on my modem, but I cannot seem to ping anything. What is going on?

There are a number of possibilities here that are generally easily distinguished with some information from the earth station when the ship is online:

1. It may be that the address you are pinging is either not turned on or is behind a firewall that blocks pings. Be certain that whatever host you are pinging is supposed to be responding to pings where you are. You might try a traceroute to see where pings stop, but this might also have trouble with firewalls, routers, and address translation.
2. There may be issues at the earth station either receiving signals or with the routing gear. This might be caused by partial power outages, planned maintenance, or equipment failures.
3. There may be a routing issue at your home institution's campus. This may be just related to the connection between the home institution and the earth station, or the home institution may have a problem with the ship's network or campus backbone.
4. If the signal is not seen strong at the earth station and the ship has a good strong lock on the shore-to-ship carrier, there may be a hardware problem on the ship. This could be a loose connector or cable anywhere between the modem and the amplifier in the dome, or it could be failed RF equipment (usually the transceiver or power amplifier). It might be worth looking at the output of the modem's Tx port with a spectrum analyzer directly to verify that there is indeed a carrier. Beyond that, there is not a whole lot of troubleshooting that can be done without a high frequency spectrum analyzer.
5. There could be a routing issue or CAT-5 cable unplugged on the ship. With frequent enough changes on the ships between cruises, sometimes the wrong cable gets pulled or the wrong access list gets updated.

I have an error light and the error code on the right of the error screen reads 0008 or 0020. What does this mean?

The error codes can be broken down into powers of two and correlated with errors listed in the antenna controller operations manual. Error code 8 probably the most common error and it is a "Pedestal Error" (see What is a “Pedestal Error”, and what can be done about it?). An error code of 16 indicates a DishScan error (usually that it is turned off and your step integral is 0000). An error code of 4 is a remote serial error indicating that the antenna controller below decks is having trouble talking to the PCU up in the dome. A combination of those last two gives an error of 20, and this is frequently seen when the pedestal is power cycled. Errors can be cleared by pressing the "up" arrow. Errors that come back immediately are usually cause for concern.

What is a “Pedestal Error”, and what can be done about it?

A pedestal error is the way that the SeaTel antenna system tells the user that the antenna up in the dome is not or cannot get where the antenna controller (below decks) told it to be. This may be caused by any number of circumstances including the following:

1. The antenna is out of balance and fighting weights to get where it needs to be.
2. Some dangling cable on the antenna frame in the dome is catching on the antenna pedestal or other structure, thus preventing the antenna from moving smoothly.
3. A drive belt has snapped and one motor cannot drive the antenna as it should.
4. One of the sensors in the dome has failed and the antenna itself is not sure where it is pointing. This usually requires a replacement of the level cage (from the spares kit) where many of the sensors reside.
5. One of the motor encoders has failed and is not sure of where its really is. This usually requires replacement of the motor and encoder (all one assembly in the spares kit).
6. The PCU has failed and cannot receive or calculate where the rest of the gear in the dome is or where it should be. This often involves replacement of the PCU in the dome (with the spare one in the spares kit, see How do I replace a PCU?).
7. The inputs for heading or GPS are changing far too rapidly (incorrectly) for the antenna to keep up and it is thrashing. This usually is a problem with the GPS or heading feed, not the antenna.

When you have determined that you are seeing a pedestal error, you can decode it (see How do I decode a “Pedestal Error”?) and/or get ADMC data to HiSeasNet technical people (see What is ADMC data and why is it useful?) to determine which axis/axes are having trouble and need attention.

How do I decode a “Pedestal Error?”

The point of decoding a Pedestal Error is to determine exactly what part of the pedestal is reporting the trouble. This generally breaks down into the various movement axes. The latest manuals have the best description of the process and the values it generates (and what parts they resolve to), but the basic procedure and common values for decoding are:

Note: Whenever remote commands are involved, please be careful. A little mistype can cause the dome to get very confused and you will never know what you did (very little output for these commands):

Procedure 5.1. Decoding a pedestal error from the antenna controller

1. While at the window (with older controllers, you may need to hit the MODE button and possibly the unlock code to cycle through all the installation parameters before you get ther) key in . , 8, 3, ENTER.
2. Press the MODE key to go to the window. Sabc@ will be displayed (S followed by 3 letters and a symbol (checksum). The fourth letter (c above) is the pedestal error letter.
3. Lookup the error using the table in your manual or the limited one below.

Table 5.1. Pedestal error decode

Letter	Az ref, encoder or home flag	Azimuth	Level/Elevation	Cross-Level	Description
	0	0	0	0	None
A	0	0	0	1	CL
B	0	0	1	0	LV
C	0	0	1	1	CL and LV
D	0	1	0	0	AZ
E	0	1	0	1	AZ and CL
F	0	1	1	0	AZ and LV
G	0	1	1	1	AZ and LV and CL
H	1	0	0	0	Ref
I	1	0	0	1	Ref and CL
J	1	0	1	0	Ref and LV
K	1	0	1	1	Ref and LV and CL
L	1	1	0	0	Ref and AZ
M	1	1	0	1	Ref and AZ and CL
N	1	1	1	0	Ref and AZ and LV
O	1	1	1	1	Ref and AZ and LV and CL

What is ADMC data and why is it useful?

ADMC data is a set of antenna position values collected by the DAC Remote Panel program (see How do I get troubleshooting information from the antenna?). With the software, a nice plot is made as the data comes in. The raw values that create that plot can be dumped to a comma separated value (CSV) text file. When that file is emailed back to the HiSeasNet staff they can do some analysis of what your antenna is doing at any given time. The file includes the antennas azimuth, elevation, cross level, AGC, threshold values, ships position, heading, etc. With an ADMC file collected during some strange antenna behavior, it is much easier to determine what might be going on.

Why is my antenna pointed up and spinning around like a helicopter?

Sometimes when the power to the dome is a little weak or has been disrupted, the older antennas would send themselves into a test mode where they looked for which direction was forward (as indicated by the “Home Flag”...a bump that triggers a switch to signal the antenna was pointed forward). With the lower power, the antenna never sees the switch that indicates the front, so it keeps spinning around looking for the flag. The solution is to power cycle the pedestal to fix the initial problem. In the longer term, newer version of PCU firmware will probably fix the problem.

I have 4 green lights, but the antenna is not tracking well or at all. When the ship moves or turns, the lights go out. My AGC is about the same when the lights are lit and when they are off.

This is usually related to having the wrong tracking frequency in the DAC. Your DAC is trying to find a signal at a specific frequency. If it is looking at the wrong frequency, the controller will keep searching until it finds something. If it passes over the correct location, your modem may lock up for a brief moment as it knows the correct frequency of the signal you are looking for. Unfortunately, the DAC will keep searching, not knowing that it just saw the satellite.

The fix to this is to correctly enter the correct frequency that you should be tracking. While the carrier you should be tracking is frequently shore-to-ship carrier that you are collecting data from, there are some situations where your ship might be using a different (larger or stronger) carrier to get the best tracking performance. When you determine what signal to track (try looking in your last maintenance report's settings section), the DAC needs to have the frequency entered appropraitely. With older controllers, this means going to the IF field, entering the megahertz numbers, and ENTER, a decimal point, then the kilohertz numbers followed by two ENTER keys (ie. for an IF of 64.800 MHz, enter: 6, 4, ENTER, ., 8, 0, 0, ENTER, ENTER). For newer antenna controllers, the interface is a little more intuitive, but there is still a separation of megahertz and kilohertz values.

My AGC shows something at least a couple hundred counts below what it should...something like 800 when it is supposed to be 1500. What happened?

You are likely pointing off into space, is blocked by the ship, or is otherwise not looking at any satellite. The low number is the noise that is normally seen by your equipment when you are not seeing a satellite.

My AGC shows a fairly steady number around 200, my antenna does not track, and my modem is unlocked. What does this mean?

You probably have a failed low noise amplifier (LNA). This is the box on the end of the feed that starts off the receive side of your RF path. When these fail, they sometimes cause a very steady low signal to be sent down the wire to your DAC and modem. C-band ships should have a spare LNA on board. Replacing the broken one (a bit tricky to get the antenna pointed down to the door while you replace it) should fix the problem without any need to rebalance the antenna.

Why is my antenna controller's threshold (THRS) value greater than the AGC?

When the antenna's AGC value (amount of energy it sees at the tracking frequency) is lower than the threshold value for a given period of time (adjustable in the DAC's extended SEARCH DELAY parameter), it will start searching for a stronger signal. If it finds a signal that brings its AGC above the threshold, it will go into tracking mode. Should this signal drop below threshold, the antenna will start searching again.

If your antenna's AGC is fluttering around the threshold value, it may be pointed at the wrong satellite, the edge of the satellite, or the signal you are trying to track could just be weak. You might try adjusting the SEARCH LIMIT parameter in the DAC to increase or decrease how far the antenna searches for the satellite.

When I enter the longitude of my satellite, the DAC finds another satellite or does not track well. What's going on? OR Why does my controller track the satellite better when I enter a satellite longitude that is off by a few degrees? OR I get a stronger EbNo a few degrees away from my last known azimuth and/or elevation. What is going on?

When antennas are installed, they may not always be installed exactly in line with the ship for many reasons. Some antennas are constructed to not be quite level, too. As a result, the antenna controller has the capability of adjusting azimuth and elevation offsets up to about 10 degrees to compensate. The trim values should be set so that entering the satellite correct satellite longitude brings the antenna quickly and directly to the strongest signal from the satellite. If the trim values are not correct, entering the satellite longitude will bring the antenna elsewhere. This might be the edge of the satellite (and a lower than normal EbNo), or even over to a different neighboring satellite where the signal is stronger. The offset might be so much that it falls outside the search limit and the correct satellite will never be found. While some techs may be tempted to just enter a different longitude to target the right satellite, this will affect the calculations of where the antenna should point and will vary as the ship moves. It is better to adjust the trim values so that the antenna points in the correct place. For more information about how to adjust trims, see How do I adjust my antenna trim values?.

Trim values should not change much during normal operations, but there are a few cases where it might. Regardless, they will be checked (and adjusted as needed) at every maintenance period.

HiSeasNet Equipment Questions

Questions and answers in this section relate to the equipment used in HiSeasNet. These tend to be related to normal operations, and not troubleshooting scenarios.

What spares do you recommend having on board?

The short answer is, “As much as you can afford or are willing to risk failing”. In general, we have found the most failures over the years to be the RF equipment on the C-band ships, the pedestal control units (PCUs) for the antennas, and the level cages for the antennas. There have been some motor, belt, and other odds and ends fail, but the majority of the catastrophic problems have been with the RF, PCUs, and level cages. We have had some rotary joint (basically a slipring) failures, but these are uncommon, somewhat expensive, and not entirely crippling (only on certain headings usually).

We recommend that every ship carry a complete antenna spares kit (they are stock with the antennas). The older and larger antenna spares kits had replacement PCU and level cages, but newer and smaller ones do not. If the spares kit does not contain a spare PCU and level cage, they should be purchased. In addition, we recommend each ship carry spare RF gear. Despite the cost, it may very well prevent catastrophic outages. A spare modem is also a good idea, but has rarely caused complete service loss.

What Spectrum Analyzer do you recommend?

In a perfect world, one would have a spectrum analyzer that was able to go all the way up to the frequency range of the real signals. For C-band, this is about 7GHz, and for Ku-band, this is about 14 GHz. Those usually cost at least $7000, usually much more (especially for the Ku-band part of the spectrum). If one just wants to monitor the intermediate frequency, a lower frequency spectrum analyzer can be used. For the C-band systems, this is in the 70 MHz range, so a much cheaper analyzer is used. For Ku-band ships, this is in the L-band range, so something up to about 2GHz is required.

In order to work, not only does a spectrum analyzer needs to have a top frequency range at least as much as the intermediate frequency, it also needs to have a bandwidth resolution of less than about 30 kHz. In many C-band locations (with 70 MHz IF), we have found the Hameg 5012-2 analyzer to be a reasonably priced (~$2300) unit that does the job acceptably. Many ships prefer to have a much more expensive system, but do benefit from the greater resolution and adjustable sweep time. We have not found a very good L-band unit that is cost effective.

The HiSeasNet project has an Anritsu MS2721A unit that handles C-band and all IF well, but was somewhat expensive. Other units that BK Precision makes have been seen as possible candidates, but we have no experience with them.

Is it a DAC, a TAC, or an ACU?

The device that controls the antenna movement is called all of those things. The oldest term (often still seen on labels in the fleet) is a TAC. SeaTel started calling it a DAC by the time HiSeasNet was started. Newer units are called (most appropriately) ACUs or “Antenna Control Units”. HiSeasNet staff will frequently refer to the antenna controller as a DAC both out of habit and to use terms that the most ships understand.

How do I replace a PCU?

Swap hardware, program type, set home flag offset The procedure for the PCU replacement is as follows:

1. Record the current parameters in the DAC just in case something should damage or change them accidentally.

2. Make the hardware swap. This involves the following steps:
   1. Turn off the antenna.
   2. Locate the PCU box.
   3. Label the connectors.
   4. Disconnect the connectors.
   5. Remove the PCU box. The mounting hardware likely has Loctite on it and may be a bit difficult to release at first.
   6. Put the replacement unit where the original came from. Preferrably use Loctite to keep the mounting hardware from shaking lose over time.
   7. Reconnect the cables properly again.
   8. Turn the antenna back on.
3. Program the PCU with your dish model. To do this at the antenna controller, do the following:
   1. Navigate the DAC to the window. This usually involves hitting the MODE button until it says “Remote Command” at the top of the screen. You may need to enter the bypass code to get into the extended menus.
   2. While at the window, key in ., 7, 8, abbrev ENTER
   3. The screen will show N0000. Enter the 4-digit code for your SeaTel model number, followed by the ENTER key. These are:
      

      0140 for a C-band 9797 2.4m dish

      0020 for a Ku-band 4006 1m dish

      0022 for a Ku-band 6006 1.5m dish

4. Double check the parameters in the DAC to make sure they are still the same as before.
5. Retarget the satellite by entering in the longitude again
   

How do I adjust my antenna trim values?

Under Construction

What is a Home Flag Offset? How do I adjust it?

Under Construction

How do I get troubleshooting information from the antenna?

Under Construction

What is “Satellite Reference Mode”?

Under Construction

What is "DishScan" and how does it relate to other scanning modes?

Under Construction

HiSeasNet Policy Questions

Questions in this section relate to HiSeasNet operations, policies, procedures, etc. They are less technical, but relate to the organization and the people of the network instead of the equipment.

How do I get a maintenance visit scheduled?

Maintenance visits are scheduled roughly every 6 months, depending on availability of ships and technicians. In an attempt to minimize routine maintenance costs, we will try to perform routine maintenance on many ships in the same port/region. By keeping routine costs down, we are better able to respond to emergency work, possibly in foreign ports. To schedule a maintenance visit when one is due, please contact Steve Foley (sfoley@ucsd.edu). He will work with people and ship schedules to find a good time to get the work done.

If you are in need of additional maintenance, installation, or other work not part of routine HiSeasNet operations, you are welcome to discuss having this done at your expense.

What happens during a maintenance visit?

When a routine maintenance visit is performed someone from CommSystems will visit the ship. They will walk through a checklist of service points confirming correct behavior, making adjustments, or performing repairs as needed. A series of photos are taken of the equipment, and another complete listing of all the settings is made. Additionally, the spares collection is inspected for adequate spares. The person performing the maintenance visit will need to take the system offline during the work, and will benefit from some interaction with the ship techs. The results of the work can be discussed with the techs, along with training regarding new features or review of old features.

What do I do with a maintenance report?

After every maintenance visit, a report is generated. This report includes images of the HiSeasNet equipment, the current settings, and the checklist used during the report, along with some recommendations and other information. This report will be archived at SIO, and will be distributed to the primary points of contact at the institution in charge of the ship. The primary contact at the institution should read the report, distribute the report to all who are interested, and file a copy on the ship. It is probably a good idea to have a hard copy of the settings on the ship, too, in case of equipment failure.

How do I get the best response to my troubleshooting questions?

Troubleshooting gear at sea is difficult, especially when people on shore need to be involved. To get the best service, it is best to send email to hiseasnet-admins@epicenter.ucsd.edu. This gets fanned out to a number of people who might help, and response time is generally a bit quicker. To be especially helpful, please include the following information as early as possible:

• Antenna AGC and THRS
• Ship latitude, longitude, and heading
• Antenna azimuth and elevation
• The longitude that is programmed into your antenna controller
• The IF or FREQ value that is programmed into your controller
• A list of error numbers that are showing up and if they stay cleared when you try to clear them
• Modem EbNo (if it locks)
• A detailed description of what is going on
• A detailed description of any corrective action you have taken so far
• Anything else you feel may be important for us to know

Having this information will help us start to distinguish if this is a problem with antenna tracking, RF operation, signal decoding, routing or something else. The sooner we can break down the problem to one of the categories, the more help we can provide and the sooner we can get spare parts to the ship if needed.

Is HiSeasNet staffed 24/7? 8/5?

HiSeasNet is not staffed around the clock. It is not necessarily even staffed after hours. The technical team makes every effort to respond to ship problems whenever possible, but is not on call or necessarily reachable at any specific time. This flexible schedule tends to fit better with the multiple time zones that ships are in at any given time.

How do I get in touch with HiSeasNet people?

The principle investigator of the project is Dr. Jon Berger (jberger@ucsd.edu). If your question is related to administration, paperwork, money, or otherwise, he can at least point you in the right direction.

Any technical issues with HiSeasNet should be sent to the HiSeasNet technical team at hiseasnet-admins@epicenter.ucsd.edu. Sending to this address instead of an individual allows issues to be addressed more quickly by the first person to get the email. You can also contact Steve Foley on his cell phone (ask him for the number). While Steve's office phone (858-822-3356) does forward to his cell phone when he is not in the office, ships may have a little better luck calling his cell phone directly as the call is then identified as an Inmarsat call.

Who do I talk to about joining HiSeasNet?

If you are interested in joining HiSeasNet, it is best to start by looking at the HiSeasNet website to get a feel for what the network is all about, how it is organized, and what resources are available. The next step is to contact the PI for the project, Dr. Jon Berger (jberger@ucsd.edu) to discuss the interest and how it might fit into the project's timeline and budget.

The way the system works is that the ships' operators usually buy there own compatible on-board equipment most conveniently through CommSystems, the local SeaTel distributer who also are under contract to maintain the ships' and shore equipment. Ron Nitz of CommSystems (rnitz@comm-systems.com) can provide a quotation for the required equipment and installation. Steve Foley (sfoley@ucsd.edu) here at SIO can provide details on the networking aspects of HiSeasNet. Each year, NSF gives us a grant to support the OandM of the ground station (at UCSD) and pay for the satellite bandwidth. The non-NSF ships are then billed for usage at a per-diem rate set by NSF for use of the system.

How much does HiSeasNet cost?

Under Construction

How do I get more bandwidth, say for short term videoconferencing?

Under Construction

Are there any mailing lists or discussion groups available?

Under Construction