There is indeed something wrong with my laptop video because
when I installed the same download on my desktop, the problem went away.
I cannot imagine what is on my laptop that can cause that problem. Do you
know of any utility that I could use to investigate this?
However the other problems I am experiencing appear to be common to both
systems. I have tried to be systematic in trying to document the behavior
but it is too erratic to make any sense of. So what I am going to do now
is tell you what happens in this one simple acquisition.
With the laptop, and a fresh boot, fire up SE as the only program
running. Set up an analog input step for two inputs, ai1 and ai2.
Use default values (1k sample rate, 1k samples to read, continuous, +/- 10
volts, differential, no scaling). This provides for a 1 second
iteration, preferably updated every second.
For the first run, the display in the ‘step setup’ updates every 9
seconds. Stop the run after a few minutes. Start the run and now
the display updates every second. Stop again after a while. Start
the run and update is again every second. Stop the run after a
while. Repeat. It is now every 9 seconds. For each run/stop
cycle in this sequence, the display update periods in seconds are:
9,1,1,9,1,9,1,9,9,9,9,9,9
I now unplug the device and plug it in again. The update sequence
becomes:
1,9,1,1,9,1,9,9,9,9,9
unplug and plug back in, and the sequence becomes:
1,9,1,9,1,1,9,1,9,1,1,9,9,9,1,1,1,9
Unpluging and pluging in the device appears to initially reset the updates to the
correct 1 second value.
Now change sample rate to 5K/s and 5K samples. The display update
sequence becomes
2,1,2,2,2,1,2,2,1,2
Even though the sampling rate has been increased, the update period has been
reduced, although it is still eratic.
Change sample rate to 100samples/s and 100 samples.
I now get error 200284 (samples have not been acquired…..)
In the ‘advanced timing’ tab of the ‘step setup’, I change the ‘timeout
(s)’ from the default value of 10 to a value of –1 (infinite).
Hit run, and the display updates at 1 second intervals. Stop and then run again and now get error
200279 (samples no longer available ….. ). Stop and run and same error. Repeat, same error.
Unplug and plug back in.
and the update sequence becomes:
1,1,1,1,error 200279,1,1,1,1,1,1,1,1,error
200279,unplug/plugin,1,1, error
200279, error
200279
So slowing down the sample rate appears to make things worse.
Switch to desktop and start at the same initial conditions
(1K etc). The sequence is:
1,1,1,1,1,9,1,1,1,1,9,9
The problem does not go away by switching computers,
although in this example it is not as severe.
I have been doing more complicated acquisitions with a lot of what
appear to be erratic problems, but they could all be related to this update
issue.
Am I correct to assume the program is smart enough to
know if there is anything wrong with the initial program download (checksum
etc.)?
