I have acquired a VM140, and wrote a C# wrapper around the k8061 driver. I have written a test application also in C# and I can communicate with the VM140 card i.e. read analog & digital inputs and set the analog and digital outputs. I have connected a VM132 temperature sensor to channel 1 of the analog inputs (the other analog channels have not been connected to anything). I chose the 5V+ option on the VM14 (jumpers closed) so the voltage input on the VM132 is 12VDC+. I have also added the 4 x 1K resistors between the out voltage on the VM132 and GND. My application does the temperature calculations and I display the Celcius and Fahrenheit temperatures in my applications. I still have to calibrate the VM132, but the values are close enough for now.
My problem: Initially the value received from the analog input seems correct, but I have left the application, VM140 and VM132 running through the night and then the values read from the analog inputs goes bad. Channel 1 will have a value of 2358 for example and the other channels (not connected) will show values greater that 0 example 10 etc.
The VM140 & VM132 works from different power supplies.
Thanks for your reply. I will make sure that I give attention to the possible causes. I have changed the app to log the readings every minute to see if I can find a pattern. I will let you know about the results.
I have looked at the possible causes but I think it is not that. Here is what I found in th logs:
Started the application at 2009/08/04 10:13:21 PM and channel 1 (VM132 sensor) had a value of 139. The other analog inputs’ values were 0.
The values stayed more ore less like this until around 2009/08/05 01:15:23 AM. At this stage the value on channel 1 was 106 and the others were 0.
At 2009/08/05 01:16:23 AM (1 minute later) the value on channel 1 jumped to [color=#BF0040]26895[/color] and the other channels had values of either [color=#BF0040]15 [/color]or [color=#BF0040]7[/color]. This was the case until this morning at 2009/08/05 06:01:27 AM. Channel 1’s value was still high and the other channels had values of either 15 or 7.
This is very strange.
First I was assuming memory leak, but the result should be more drastic in that case.
You may run the same test with some other example program (e.g. the Delphi one).
The problem is that there is no log file generation and you have periodically check the AD bars on the display.
Is the time to problem occurrence always the same (about 3h from startup)?
The test number 1 will be good reference.
It may be even more informative if you connect some (clean) voltage to the analog input e.g. from 1.5V battery.
Hi all,
I have the same problem.
I’m using the card in a domotic system, With AI I read Temperature sensors (analog devices AD22100, 22,5mV/°C) powered at 5VDC directly by the LM7805 on the board (but I have tried with ext power supply too).
Sometimes, the analog reading is completely wrong, higher than expected.
I checked with a multimeter and don’t depends from the sensors or power supply.
Powering off the sensors for few seconds and powering on, the measurement is good up to the next fail.
There is a strange thingh… on digital inputs I connect PIR sensors, normally (but not only) the fail happens when there is movements in the rooms…
Hi,
a lot of years from the last post, but the problem is the same!
My domotic is growing and now I’m using two VM140… both with the same problems on the analog inputs.
Seems that AI goes wrong toggling the DI.
The AI restart if I power down the Board so when the application detects “stange” AI values, move a DO, connected to a monostable relè that switch off the power to the board.
Bad solution… Has someone a better solution or is there a FW upgrade for the board?