Last edited 27 July 2008

GB3RAL MONITORING ---  REMOTE CONTROL OF COMPUTERS ----  NETWORKING ---- EXCEL

19 May 2005 A quick rundown of my experiences with a remote computer. Getting closer to maintenance free, apart from hardware failure.

 Pentium 90 48MB RAM W98SE. May run for months, then might freeze several times in a week. (Data loss overcome by freeze detector/reset circuit) Now the time is set by MSF there is no point in having any control of the computer. (No VNC, mouse or keyboard) When the Beacon program is setup it will restart properly from a reset or power loss. Programs started by shortcuts in Start Menu:- Beacon program, Cron, MSF for Windows. Cron schedules uploads of data etc. Connected to internet through Ethernet to router. The hardware firewall in the router seems to make it invisible, no software firewall or antivirus is used, it has never been attacked. (Yet!!) Log data, editing Crontab etc. achieved via Ethernet. The RX, Icom R70 now has an external memory backup battery to ensure it survives a short power cut (No internal battery (20mA!)). A longer cut could cause it to restart too far off frequency due to its somewhat high temperature drift. Note it is not necessary to terminate the program to edit the log file. In the inactive period before the next sequence I routinely copy the log to my archives and delete all but the last 48 hours so the file does not get unnecessarily large.

May 2006 Current setup

For a long time I was convinced that a separate monitoring computer was almost essential in order to avoid discontinuity of recordings. However, the desire to make other long-term observations prompted me to build up one that could be used for everything. It is a Pentium 350MHz with 324MB memory running Windows 2000. It has on-board sound, that I use for the Beacon program, and two other soundcards that are usually used with SpecLab to record signals to check for the presence of Greyline/dusk/dawn enhancements. (See main index) After a couple of "freezes" occurring in quick succession I built up an "anti freeze" circuit like that for my Windows 98 computer. I have not yet fitted it, the computer has now been running 3 months without a restart even though I am now using it for internet access, email checking etc.

This only includes continually running processes, SpecLab loads the CPU around 35% for many hours each day. 

February 2007

The monitor computer is now a K7S5A board with XP1900+ (1.6GHz) and 750MB running XP. To enable a restart after a power interruption I made a small modification to the board so it will start the power supply when mains power is applied. I am now experiencing the problem of having used it too much! For the first time for a long while the monitor computer is unstable, something is causing it to freeze. Sometimes this seems to have lasted for hours before XP got round to rebooting. I have added a "freeze reset" as above while I try to isolate the problem so interruptions are small. The original Pentium 90 is recording the 5MHz beacons. My usual technique is to waste an enormous amount of time attempting to rectify a fault so that Windows reinstallation is not required - the outcome often is that that time IS wasted! 

REMOTE MONITORING

This project involves extended monitoring. I have used a remote computer, To check that things are going well it is possible to read and copy the .log file on the home computer by means of a network connection. Full remote control is possible using a FREE program, see VNC below.

The computers can be connected with only a "crossover" cable. If, like me, you use second-hand computers you will find many business computers will already have a network card. If not new ones are not expensive, old TBase10 cards are very cheap. I have even made my own "twisted pair" network cables. although that is probably taking home brew a bit far for most! Some notes on Networking below. PC in Garage, extensions go to panel on right. Keyboard connects to two computers.

The remote computer may be operated with the same mouse, keyboard and monitor as your main computer. There are proprietary "KVM" switches and extension leads available. Or, make your own.

Simple mechanical switches may be used to switch the keyboard, video and mouse.

A couple of cables from old colour monitors may be used. a 5 pole "break before make" is needed, a three way rotary with the centre position unused would ensure that. I used an old "Post Office" switch. The earth connection must not be switched.

The keyboard may be switched with a 2 pole changeover, can be mounted in the keyboard. This switches the Data and Clock line to one or other computer. The grounds are connected together. The positive feed comes via a diode from each computer to the keyboard.

I have recently installed a "wireless" keyboard and mouse, the receiver unit will not work with series diodes so I used a relay, solid state switching could be used. 

The mouse is small enough to just use a separate one, otherwise a similar switch is needed.

Plug leads from old keyboards and/or mice may be used.

The simplest commercial "KVM" switches use this technique implemented with "solid state" switching. This, of course could be done with some 4066s.

I do not know the minimum computer requirements for GB3RAL, I have run it on a 75MHz machine with 16MB RAM, an ordinary video card and a 400MB hard drive (A basic W98SE installation leaves 190MB free).  Any sound card seems to work, I have used one that was designed for DOS and only works in Windows with "hacked" software.

On a 100 MHz with 24MB RAM I have run GB3RAL, a screen capture program, internet time setter and VNC Server (See Below) with W98SE.

JUNE 1 2004 I am now using a "minimum" computer setup. After installing Windows and GB3RAL I have removed the floppy and CD. It is controlled with VNC (see below) No monitor, keyboard or mouse.

Once setup most computers will run without a display, can be set to not require a mouse, (Control Panel - Accessibility Properties - Mouse - Use Mousekeys) (When the "No mouse detected" window comes up use the TAB key to highlight the "Do not tell me again" box, + key ticks it.) 

SOME will run without a keyboard! (I wonder how many? I've got three that do not complain when no keyboard is connected!) One could remove the PCB from a keyboard and just connect that to save space. If a GB3RAL shortcut is put in the start-up menu then no control is required. Set the TIME accurately before disconnecting. If GB3RAL is run continuously, with only short stoppages, it will track the beacon indefinitely.

NOTE If any significant period elapses when GB3RAL is not run then the computer time and GB3RAL will need to be reset.

If a W95/98 computer is just switched off, when it is switched on again it just goes through the "Scandisk" routine and restarts. (Works quickly on a basic installation and finds no errors.) GB3RAL will open the .log file and write to it, (Provided you have previously enabled "Write to File")

Installations of Windows 98 have a reputation of instability. My monitor computer randomly becomes very stable, freezing and doing nothing! This can occur after several months of continuous running or just several hours. As mentioned below, this computer has apparently been caused to  freeze by unusual signals on the network, eg. a fault or an attempt to setup the network on another computer connected through the router. Quite a long time could elapse before I notice, I have now installed a simple circuit that resets the computer when it freezes. This is a basic R/C timer that is reset when the hard drive is accessed. This normally happens every 15 minutes when the computer is operating correctly. If it freezes nothing happens, the timer completes its cycle and resets the computer. When I first installed it the computer reset 3 times in a week, I thought it was resetting due to a fault but has now run for 4 weeks.... When it has reset one or two loggings are missed, better than many hours!  . . It is a 4011 IC and a few components, details on request.

TIME

NOTE it the power is interrupted the beacon program timing will need to be setup as the settings are only written to disc when shut down normally. One way to avoid this is to keep the time of the computer set exactly.  Some Notes about Radio Clocks  For continued monitoring without intervention the beacon receiver  must not loose it's settings either.

If a keyboard is connected W95/98 can be turned off by entering Windows key (or Ctrl-Esc) - U - S - Enter. It may be necessary to press Enter again if it tries to tell you there is a Network connection open.

In this configuration the computer can be stored somewhere, upside down, on its front/side just as long as the ventilation is not obstructed. The mains, audio and Ethernet cables are all that need to be run from the computer.

If a speaker is connected the Beacon can be monitored at the remote location. (Speaker can be located internally, even cards with only a "Line Output" can provide adequate volume to a speaker)

A monitor may be temporally connected to setup or check/alter operation. For safe connection/removal when the computer is running only connect or disconnect the monitor from the computer when the monitor is switched off and disconnected from the mains. (Avoids any possible earth returns from going through the video card/monitor circuitry.)

I have three computers with the program installed, the levels are setup to be almost identical, I can just transfer the log and continue on another.

CONNECTING TO COMPUTER

Checks should be made that no earth loop is present, it is best to use an isolating transformer for the audio (From an old modem?) Keep this transformer away from mains transformers otherwise it could cause far more hum than an earth loop!

I was not using isolation, due to a potentially lethal ground fault in my garage wiring I destroyed the on board sound IC's line input by reconnecting the plug. (I wondered why I got an electric "tingle"! After repairing the garage wiring the IC continues to work with the input applied to the internal CD plug. Until this happened I was scornful of advice to switch off and disconnect from the mains before connecting/disconnecting items!

When connecting a radio with an external power supply to a computer for ANY purpose COMPLETE isolation should be considered, if the negative power supply connection to the radio is faulty all the radio's negative return current will try to go via the computer/radio connection leads and possibly through the computer boards.

VNC - Remote control of computers via Ethernet and/or Internet

There are different releases of VNC, (Check Google) I have only tried the "Tight VNC" so far.

Thumbnail on right shows two monitoring computers both controlled via VNC on a third computer. Click on image for full size. The gl590 computer has a 75MHz CPU. Note using VNC the time in the Title Bar does not update. 

 Tight VNC (Click link) remotely controls the monitoring computer. The version I have used is described by the developers as "unstable" but so far I have had no problems, although my usage does not tax it much. There are earlier versions on their site. 

It does indeed enable complete control of a remote computer. I have used "Tight VNC" to run GB3RAL, everything is available. The "Viewer" computer's mouse and keyboard control the "Server", slower, but as if it were directly connected. Files may be read/transferred and programs started/installed and the computer closed down. I have even installed a newer version of VNC via remote control, the remote computer restarted with the new version running! Tight VNC is configured to make this possible.

Once setup the remote computer needs no screen,  mouse or keyboard (but some will require a keyboard connected to boot up) Ensure that networking is working properly before using VNC. If VNC is set as a "service" it will start with "Windows".

The server computer will sit there indefinitely, can be viewed at any time. Note the password is case sensitive.

The computers were 75 and 400 MHz, 10MBPS LAN. Win98SE. The computers can be connected with a "crossover" Ethernet cable or via a hub. There is a time delay, so setting the time on the remote computer will require compensation. 

When the power was momentarily interrupted the network connection was lost, switching the monitoring computer off then on again restored the connection. Then I was able to inspect the .LOG file and reset GB3RAL.

Ignore this device when monitoring for extended periods! (Or compare the estimated consumption with the cost of your latest rig.)

NETWORKING

There is a lot of information about networking on the web.

IF you make up any Ethernet leads the contacts of the RJ45 plugs may be carefully pushed into the wires by using a screwdriver blade with a suitably sized FLAT end. Maplin sell split plugs but the net will provide ready made leads cheaper, even allowing for postage. 

My brief summary of experiences follows.

Older network cards MAY give problems. ISA ones especially may conflict with the soundcard preventing one or the other from working. I have had that happen several times, Windows gave NO CLUE that anything was wrong!

Do not rely on the LAN indicator lamps. One computer had both lit, one was a 100Mb/s indicator when only a TBase10 cable was fitted! Due to a bad contact I found that a very small amount of information can be transferred by a single pair of wires, everything seemed to be OK but almost no operation.

Two computers can be setup to "see" each other by using a crossover cable.

Both will need to be setup via "Network" in Control Panel.

Each computer has to have a unique name. (Identification)

Each computer must belong to the same "Workgroup". XP insists on bringing up "MSHome" every time, easier to use that.

Install the same protocol on each computer.

IPX/SPX-compatible Protocol is needed if Windows XP is involved with non XP systems.

Enable NETBIOS support for IPX/SPX-compatible Protocol.

The XP "Network set-up" floppy did not work when I tried to use it with W989SE or W95.

Enable File and Printer Sharing on the monitoring computer. 

Enable sharing on each drive. Go to "My Computer" right click on a drive and select "Sharing". Windows networking can give problems due to security issues. I found a computer running W2000Pro would see other computers but not allow itself to be seen. I finally got over this by creating a "New Share" for each drive. (Possibly caused by the way I had the Administrator account set?)

Select "Windows Logon"  as the Primary Network Logon.

One computer I use does not enable the networking unless it is started with an active connection.

The log file may be edited via the Ethernet connection, provided it is done when the program is  idling between beacon sequences. 

My W98 computer has frozen when connected to my router when attempting to setup the network on another computer and also when there was a cable fault to another computer. I presume it did not like the "Probing" signals transmitted by the others.

If "Network Neighbourhood" does not show anything try "Find Computer" on Start Menu. Enter the unique name.

If you use the internet ASDL (telephone) or DSL (cable) consider the use of a "Router". Even ordinary dialup connections are vulnerable to "network worms" that probe for computers without a firewall and install malevolent software without your knowledge.

All routers seem to include a firewall, shared internet access to each computer and a network hub (Switch?). Just connect each computer with a "straight" Ethernet cable and forget. I don't like spending money but £30 including cables and post.. 

I have seen it recommended even for one computer because of the firewall. I would NOT recommend discarding "Zone Alarm" though! A good software firewall will inform you if any program (eg a "virus" you did not know you had!) is attempting to access the internet (Not the XP firewall!). 

Three Beacon Charts produced by my crude implementation of Excel.

  If you have Excel  click this for the xls.zip  Open Office (Seems similar) or other software could be used, but you are on your own!

I am pretty well a beginner in "Excel" so this is written for beginners! Save a copy of my file, then you can do anything and start again. Most likely you will improve on my effort and save that instead!

Data can be used straight from the log file, or, copy and paste from it into a new .txt file. My .xls is configured to start from an "even" hour eg 0000 or 0200 etc. Starting at any other time will still produce a chart. Do not leave an empty line or the header at the top of the .txt file.

My .xls file contains a Macro, this is a security issue as, like a virus, it is a script. I am not sure if a virus protection program would detect a virus in a Macro, I imagine it would. When you open my .xls you will get a warning, do you want to enable a Macro in this Workbook? I can only say that it is one I prepared so there is no reason to fear it. 

When my .xls is opened it will show a chart I prepared earlier. Say "Yes" to macros, ignore the "32000 data points" message. Delete column F completely. Use keyboard Alt-E, D. (Just delete data in "D" in the old single beacon version).   Now go to "Data - Refresh Data" Navigate to where your file is stored and select it.  The "drop down" enables you to select "all files" so the file can be read directly if it does not have a .txt extension.  "Import". The new data appears on Sheet 1.  My macro Adds a column so the formatted time appears in  column "F". "Tools - Macro - Macros" (Or, easier press ALT-F8) The Bcon3 macro should be run.   If you input more than 7 days column "F" will need to be filled to the bottom. Select the column and drag the "handle" at the bottom of the filled section to level with the bottom of the data. 

Click on the "Chart" Tab. Right click on grid lines to alter the scale. Right click on the chart background to change title, right click on the plot lines to change colour etc.  If the chart is not correct the data may be edited, or, start again with an edited text file. Do not save changes! Keep an unmodified copy of my original .xls

"File - Save as a Web Page" will give a .gif image of the Chart. Name it, save it. This gives a .htm file and a Folder with your chosen name. The chart will be in the Folder as "image001.gif" If they are not required delete the other files.  An image program will add text, (Paint, Irfanview etc.), a chart with a lot on it can be resized horizontally to improve clarity. For upload use IrfanView. or similar to convert (Save As..)  to PNG format, similar quality, less than half the file size. This has a batch facility to convert a lot in one go.

A refinement could be used to produce a frequency drift Chart. (If a beacon gets locked to GPS it would be a super RX drift monitor)

 [Click here for my Excel single beacon "workbook" This is out of date, will not work with new 3 beacon program, but could be used with the original log format.]

I welcome advice from someone who knows Excel better than me, how do you fill a column just to the bottom of data? Until I "merged" two macros I was getting a REF! on the Y axis data after refreshing the data. What does the 32000 data points mean when the chart appears to be drawn correctly?

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