Monarch Instrument DC 2000 - Manual (Page 46)

Page 3-16
Chapter 3 Getting Started
3.9.1.1 Scale Ends
Use the arrow keys to select Scale Ends and press ENTER. You are presented with a menu to select
the number of decimal places that will be presented, 0 - 5. Use the arrows to select two places and
press ENTER. We will assume that we wish to present the percentage scale from 40 to 80 percent
only across the screen effectively expanding the resolution that we can see. Enter a low value of ‘40’
and press ENTER. You will then be asked for a mid-scale value. The scale can be made nonlinear by
entering a midpoint which in fact is not midway between the two end points. The advantages of this is
described in the Using Scaling Section at the end of this chapter. Keep things linear by selecting the
midpoint as being 60 which is halfway between the 40 and 80 end points we chose to select. Use the
RIGHT Arrow Keys to position the cursor under the ‘5’ which is default and press ‘6’. The display
should read ‘60.00’. Press ENTER to accept. For the high value, enter 80. Press the space twice,
enter ‘8’ so that the display shows ‘80.00’ and press ENTER. You will be returned to the Scale Pro-
gramming menu. Programming of all scale options including scale type, scale ends, scale grid and
scale units is covered in Section 5.5.2.
3.9.1.2 Scale Units
The Scale Units can be programmed in percent to match the output scale programmed in Section 3.8.3.
Once this is done, press Exit twice to return to the Main Programming menu. We have just pro-
grammed Point 1 to be a live input of 0 - 1 volts which will be scaled to an output of 0 - 100% and we
have chosen to display between 40 and 80% full scale on the display and this is what will be recorded
to disk.
The user can now program the other points in a similar fashion, simply selecting the point number and
choose to copy point 1 into points 2 and 3 or program these from scratch. It is suggested that the user
fully reads the rest of the chapters of this manual to become familiar with the functions of the various
menu options.
3.10 Recording Data
The recorder saves data, on command, to either 3½ inch floppy disk, PCMCIA memory card or a Zip disk depend-
ing on which option you have. The disks are MSDOS™ compatible and can be read on any IBM PC compatible
with a 3½ inch floppy drive, PCMCIA drive Zip drive. Data is stored on the disks as individual pen files with additional
files for configuration and alarm/event logging. Any DOS or Windows file manager can be used to move, rename,
erase or archive the files. Recording may be started or stopped manually, by an external event or on internal alarm.
Each of the 15 points may be recorded at different sample rates, or the user can choose to record all points at the
same rate. This enables slowly changing parameters to be recorded at a slower rate than faster changing signals.
Also the user can choose whether to store data in average or instantaneous modes.
The amount of data that can be saved depends on the number of channels and the sampling rate; both param-
eters can be set by the user. A 3½ inch 1.44 Megabyte floppy disk holds approximately 700,000 16-bit
samples, a PCMCIA Flash Card holds approximately 10,000,000 samples for a 20 Megabyte Card, and a Zip Disk
holds approximately 50,000,000 samples for a 100 Megabyte Disk.
These numbers must be divided by the number of channels and the sampling rate to determine the total storage
time for the disk. For example, using a 3½ inch 1.44 Megabyte floppy disk, recording four channels at 1 sample per
second, the total recording time is:
700,000 divided by 4 (channels) multiplied by 1 (second) = 175,000 seconds or 48 hours.
If the sampling rate were changed to 60 seconds, or 1 sample per channel every 1 minute, the recording time
becomes 120 days.
There is an option that allows the recorder to recycle data on the disk. The user can also store other types of data
on the disk. Configuration files contain information about how the recorder is set up and uses the space of around