Vernier LabPro - Manual (Page 8)

Revision Date: 08/02/02
LabPro Technical Manual 8
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The communications with the host are turned off during sampling.
Note: In FastMode sampling, it is very important that the program not issue any commands until after
sampling has been completed. If LabPro receives any command, it will abort FastMode sampling with an
error in order to respond to the command.
Data Collection Mode Comparison Table
The table below shows some of the differences between the data collection modes.
Realtime Mode Non-Realtime Mode FastMode
Order of data returned
when doing the GETs
from the host
computer
(n = # of samples
taken)
{ch1_1, ch2_1, …
deltatime_1}
{ch1_2, ch2_2, …
deltatime_2}
:
:
{ch1_n, ch2_n, …
deltatime_n}
{ch1_1, ch1_2, …
ch1_n}
{ch2_1, ch2_2, …
ch2_n}
{ch3_1, ch3_2, …
ch3_n}
{ch4_1, ch4_2, …
ch4_n}
{time_1, time_2, …
time_n}
Same as Non-
Realtime
Number of samples
limited? Not limited by LabPro,
but may be limited by
the host computer Yes, limited by
available memory in
LabPro Same as Non-
Realtime
Sample time limits
(approximate) This is determined by
host communication
speed. Sample Time
> 0.002 second to
≤
16000 seconds
Sample Time
≥
1e-4
seconds to
≤
16000
seconds
Sample Time
≥
2e-5
seconds to
≤
1e-4
seconds
Number of channels
limited? Yes, only CH1-4 and
11, 12 No Yes, only a single
channel from CH1 to
CH4
Can use Triggering? Not by LabPro,
performed in host
software Yes Yes, however, manual
triggering is not
available.
Communication
maintained during
sampling? Yes Yes No
Notes:
1.
Checksums are not returned when in ASCII mode communication with a computer, but they are
returned when using binary data transfer.
2. In Non-Realtime Mode, any post-process data will follow the input data for the respective channel.
In addition to RT and NRT modes, there is a single point mode. Using Command 9, a single point of data
may be read from an active channel. No time is associated with this reading. This command is extremely
useful for monitoring inputs, checking status of channels, and for very long term collection that may be
statistical or have the time base controlled by the host.