Data Logging and Retrieval ... go for quality not quantity
Unloading Data
Logged data is unloaded from internal or card memory by:
U
source schedule
(
start point
)(
end point
)
source
I - from internal memory
M - from memory card
none - unload from the memory card then
if same data set, internal memory
schedule
A,B,C,D, or X - schedule
none - unloads all schedules logged
(
start point
) (time,date) or (time)
BEGIN - from beginning of stored data
LAST - from end of last unload
none - from beginning of stored data
(
end point
) (time,date) or (time)
END - to end of stored data
LAST - to end of last unload
none - to end of stored data
All are optional, however an (
end point
) can only be
included if a (
start point
) is included. Some examples are:
Uunload all data, oldest first
U(LAST) unload most recent unloaded data
UA(BEGIN)(LAST) unload schedule A from beginning to
the same point as previous unload
UMB(12:00,19/1/91)(12:00,20/1/91) unload Bschedule
data from memory card between the two times
The oldest data is returned first and the schedules are
merged chronologically in X,A,B,C, then Dorder. The
format of unloaded data is the same as for real-time data
(see page 5). During an Unload the /r (return), /e (echo) and
/m (error messages) switches are disabled. These are
returned to their previous state on completion of unload.
Data is not cleared from memory by Unload operations.
Quitting an Unload
An Unload operation is aborted by the Q quit command.
Time and Date Stamping
The scan Time and Date can be prefixed to the data
unloaded from each schedule by enabling the /T and /D
switches. This can be done even after the data is logged.
Time and Date prefixing defaults to OFF (/t /d).
Logging Status
You can check the number of data points stored and
the free space with commands and system variables:
STATUS lines 5, 6 and 7 (or STATUS5 STATUS6 etc.)
1SV Internal data points free
2SV Internal data points stored
3SV Memory Card data points free
4SV Memory Card data points stored
Clearing Stored Data
You can clear logged data anytime with the commands:
CLEAR clears all data logged in the internal memory
and disables logging (LOGOFF)
CLAST clears data in internal memory or memory card
card that has been unloaded by U command
i.e. only if all schedules were unloaded.
CDATA clears all data logged in memory card
RESET clears internal memory (and program)
but not memory card data (or program)
The CLEAR command may appear to fail if logging is
enabled, because new data is logged soon after the clear.
The solution is to first stop the logging with LOGOFF or H.
When the commands are copied into the program area of
the memory card, these are appended to the current
contents of the program area. If there was a previously
stored program on the memory card, then the new program
is appended to the old program. The old program must first
be cleared by a CPROG command if not required.
The STATUS command returns the used and available
space in the program area of the memory card, and
STATUS8 also shows the full program listing.
NOTE: The syntax of the card program is not checked
until the program is actually run. Check the program by
executing the RUNPROG command while the card is
inserted, or by removing and re-inserting the card. Inserting
a card causes immediate program execution (if /Q is set to
the default in the Datataker – see below).
When is a Card Program Run ?
When you insert a memory card into the Datataker, any
program on the card is normally loaded into the logger,
compiled and run immediately. Datatakers with a display
will show the message Prog. You can stop automatic
loading of card programs by setting the /Q switch to /q.
The program on an inserted memory card can be
loaded and run by the RUNPROG command. This executes
a card program immediately, irrespective of the setting of
the /Q switch. Only the /F switch will prevent the execution
of the RUNPROG command (see "Switches" on page 11).
Transferring Data to the Card
Normally data in the internal memory is transferred to
the memory card after any card program is executed. The
transfer can take up to 100mS.
Datatakers with a display module will show the message
Append, depending on whether the data is appended to
existing compatible data, and shows the message Xfer
when the transfer occurs.
If the card already holds data from a different program,
then no transfer occurs and Datatakers with a display will
show the message Can't Copy Data .
When a single memory card is to be used to recover
data, and to reprogram the logger, you must transfer the
logged data before reprogramming. This is done by using
the COPY command in the program to force data transfer
before the logger is reprogrammed:
;COPY
;LOGOFF CLEAR CSCANS
;RA10M 1..5V LOGON
Automatic data transfer from the internal memory to card
can be prevented by placing a ;NOCOPY command on the
first line of the card program. The NOCOPY action is
automatically cleared when the card is removed.
Clearing the Memory Card
The data storage and program areas on a memory card
can be separately erased as follows:
CDATA clears all data
CPROG clears the card program
CTEST clears data and program, and tests
the entire card
CDATA and CPROG commands can be executed from a
card program. However CPROG must be the last command
in the card program, since any commands after it will be
cleared from the card before execution.
Removing the memory card's battery for more than two
minutes also clears the card.
Memory Cards and Programs ...added convenience
Introduction
The Datataker has two locations in which to store data:
- the internal memory, which stores13,650 data points
- PC Card (PCMCIA) memory cards, which store up to
343,980 data points in a 1Mbyte memory card
The management for the internal memory and memory card
varies according to the state of an inserted card as follows:
• If an empty memory card is inserted, the Datataker will
transfer any data in the internal memory to the memory
card, and then will continue logging to the card.
• If a memory card containing data from the same program
is inserted, the Datataker will append any data in the
internal memory to the memory card, and then continue
logging to the card.
• If a memory card containing the data from a different
program is inserted, the Datataker will not transfer data from
internal memory to the card, but will continue logging to the
internal memory. If you issue a CDATA command to clear
the memory card, then data will be transfered after clearing.
Data Logging Commands
Data logging is globally enabled by LOGON and is
disabled by LOGOFF. By default data logging is disabled.
How Data is Stored
All data is logged as 24 bit (16 bit mantissa) floating
point numbers. Internal calculations are 32 bit floating point.
Each schedule stores a three byte header per scan for
identification, scan time and scan date. When logged data is
unloaded this header and the original schedule are used to
interpret the data. Schedules cannot be replaced when data
has been logged, until data is cleared by CLEAR & CDATA.
Stop When Full Mode - /o
By default, data logging stops when the memory is full –
the earliest data is retained and the most recent discarded.
If a memory card is used, the internal memory is used only
after the memory card is full.
Overwrite Mode - /O
Alternatively the oldest data may be overwritten when
the memory is full. This is invoked by the /O switch. The
internal memory is not used in overwrite mode when a
memory card is used. You can change the /O mode switch
at any time, however the internal memory does not become
available if a memory card is in use.
Storage Capacity
Data storage capacity is difficult to calculate because of
the three byte header per schedule per scan. If the three
byte header is considered as a channel, then the following
figures are reasonably accurate:
Memory Capacity (readings) Total (card+internal)
Internal 13,650 13,650
512K PC Card 169,260 182,910
1M PC Card 343,980 357,630
Time and date in a channel list are handled as any other
channels, i.e. three bytes each. It is more efficient to use the
/T and /D switch commands - see pages 6 and 11.
Not Logging Channels
All input channels in RA, RB, RC, RD and RX schedules
are logged after the LOGON command is issued. The NL
(No Log) channel option prevents logging of individual
channels. The W (Work) channel option prevents logging,
return and display of the channel data.
Introduction
The Datatakers support PC Card memory cards which
conform to the PCMCIA Type II standard. PC Card memory
cards of up to 1Mbyte in capacity can be used.
The memory cards increase the storage capacity of the
Datataker, and because the cards are removable they are
also a reliable media for transporting data and programs.
For maximum reliability, do not expose the memory card
to temperatures over 45°C for extended periods, to ionising
radiation or to static electricity discharge.
Replace the lithium battery annually, using the same
cell or another cell recommended by the card manufacturer.
Card Specific Commands
There are seven commands specifically for managing
memory card operation:
CDATA clears card data
CPROG clears program space on a card
COPY transfer internal data to the card
NOCOPY disables transfer of data to the card
CARDID="
text
" assigns a card ID
CARDID returns the card ID
RUNPROG forces running of card program
CTEST clears data and program, and tests
the entire card
Card Identification
You can name a memory card with the command:
CARDID="
label text
"
The
label text
can be up to 40 characters, of which the
first 16 are displayed. This text is shown on the lower line of
the display when you insert the memory card. It is also
returned in response to the command CARDID.
Card Formatting
New Cards are automatically formatted when inserted
into the logger, and are given the default CARDID="
xxx
KB"
where
xxx
is the size of the memory card.
Card Processing Flow Chart
When a memory card is inserted into the Datataker, the
subsequent processing and actions depends on the status
of the memory card and the status of the logger.
The tests performed on the memory card by the logger,
and the actions taken as a result the tests, is detailed in
Appendix - "Memory Card Processing Flow Chart".
Programming from Cards
A memory card can hold a Datataker program of up to
4090 characters. Commands are entered into the Datataker
in the normal way, except that each line must begin with a
semi-colon. The logger copies lines prefixed by a colon into
the program area of an inserted memory card. For example:
;CSCANS CALARMS
;/m /n /u P22=44 P24=13
;ALARM1(1V>55.0)4DSO
;ALARM2(5TJ>107.0)"Temp. Alarm"
;RA5M 1V 5TJ 2HSC
;LOGON
Note: If a program in a write protected PC Card memory
card includes a RESET command, then the Datataker will
suspend operation until the card is removed, or the write
protect switch is moved to the disabled position.