During CHABLIS, we are intending on utilising the data management system that currently exist at Halley. A Local Area Network (LAN) connects all the permanent platforms, including the CASLab, and will be used to back-up data on a central linux server called Zenta that is located on the Piggot platform. There is a permanent data manager at Halley who ensures that the data is regularly backed up. Data are returned to Cambridge on tape at the start and end of the Antarctic summer season.
LAN (Local Area Network) connection points will be available on bench and ceiling level trunking via CAT5 UTP PATCH cable (RJ45-RJ45, 3m length, provided by BAS). The LAN will allow data file copy (and archive) to the main server.& This offers redundant security for local drive data file i/o (to cover for local hard drive failure). In order for the instrument loggers to record data on the central server, the pc must have a standard network card, windows driver and up to date operating system.
Windows NT and 2000 are the preferred operating systems. Windows 98 and 95 are also okay. Windows XP 'should' work but is not supported by BAS so you should probably bring your pc here first to test it. DOS loggers are not supported.
It is important that your instrument can log locally (eg to a c: drive) as well as remotely in the unlikely event that the LAN fails. It is therefore recommended that your software can recognise the logging status and switch to the local drive if necessary.
You must supply all spares for your computer system that might be required as well as back-up cd-roms for the Windows driver and any relevant software.In order to prepare for the approaching seasons, we need to know an exact description of the pc's that are coming to Halley during both the first and second summer seasons
Please can you therefore send Rhian and Stephane information about:
Please let us know if you DO NOT want to write data to the network (drive mapping) and would rather take responsibility for logging data locally.
The CASLab central computer will handle data acquisition for all BAS core and overwintering AFI instruments if required. It will consist of two industrial rackmounted PCs with the LabView software installed for logging instruments. Spare analog and digital channels will be available. Besides instrument logging, the central PCs will be used for logging various lab environmental status (eg lab gas detection system alarms, inlet sample flows). Note that if you require data logging or control, the prefered interface is serial RS232 (again many spare channels will be available). The central PC will have a 5 input 15.1" TFT LCD/keyboard/mouse/speaker rack-mount drawer (Wordsworth Tech part No. LKM-9265B), which can be used by other CPUs if needed (this to reduce too many VGAs in the lab). In terms of instrumentation status, control, fault reporting and relaying to the main base at Halley, we are using the Virtual Network Computing (VNC) software (get free download HERE ) which can allow complete control of the host using its IP address on the network. This may solve the problem of upgrading instrument drivers into the LabView format to allow remote access (LabView also has built-in remote access computing facility).
Since BAS uses Novell Netware Client, this would be the preferable netware client to have on your system although anything that can map drives onto the network is suitable. Please let us know what system you use. If in you are in any doubt as to the compatibility of your system, please bring your p.c. to Cambridge where we can test it. (This could save many headaches and a lot of time at Halley!)
"Tardis client" software (for NT and 2000 only) will be used to synchronise local pc clocks with the Halley central GPS time and thereby to synchronise data time-stamping for all the instruments. This can be installed ahead of time from http://www.kaska.demon.co.uk or at Halley .
The software operates transparently under Windows operating systems and speeds or slows down the processor to match the server GPS time. If you think this may effect your data logging, please test the software ahead of time. We can test the software at BAS or you may opt out. If you choose this, we'll synchronise clocks the old-fashioned way (solar dial in summer and stars in winter).
Data Transfer and Storage
Twice per year, Zenta is back up up onto tape and brought back to the UK. Ie. all data from Summer 2003-04 will be returned to the UK in March 2004. Data from winter 2004 will be back in the UK by February 2005 and the rest of the second summer season data will be back by April 2005.
In addition to receiving the complete set of raw data at the end of CHABLIS, we will also be able to send data back to the UK on a weekly basis by scheduling a satellite connection specifically for transferring data (i.e. not emails). Since it takes approximately 2 minutes to transfer 1MB of data, we will likely have to compress this data before sending it, or find an alternative way of reducing the file size. Examples include file compression, sending data with a lower time resolution or exporting data (eg chromatograms) into ASCII fomat before sending them. It is the responsibility of the University partner to develop a simple way to produce files that they would like sent to the UK on a regular basis. Following a data sched, the reciprocant is sent an email directing him/her to a website from where s/he can download the data. Obviously, we are hoping that people in the UK will analyse their data regularly so that we can know if any changes need to be made during the campaign and also look out for interesting science that could be occurring. It would be reasonable to think that we could send about 10-20MB data per week TOTAL (for all CASLab experiments) so we must know soon what data volumes to expect.
In special cases (e.g. for troubleshooting an instrument), data can be sent via an email. We will also be able to send you digital photos of your equipment for any specific questions. There is a 1.7MB limit on email attachments and these also take 8kb/second to send. This method is, however, not encouraged for regular data transfer.