computer running Dasylab loses time

[Cruiser_kidd]

I am running  simple a DasyLab application using a DakBook 200 scanning a DBK 42 module with 16 TC channels at 1kHz. When the acquisition is started I will lose 11 minutes of time time on the PC clock in 1 hour. The time loss "or lag" is a linear function with the length of total acquisition time. If I lower the sampling rate to 500 Hz, the lag is about 33 sec/5min or 6.6 minutes / hour. The saved Data is OK since it is using the DAS clock once the acquisition is started. The problem is that events were noted using the PC clock which will not correspond to the time stamped data file. Any suggestions on the cause of the clock lag?  Thanks, Cruiser_kidd

[MHa]

Hello,

there are following reasons possible:

1) DAQBOOK 200 + DBK 42 scannings needs internal with the API functions from hardware producer IOtech driver more time as the Experiment setup settings from DASYLab worksheet itself. Please contact your local IOtech dealer for this problem, it's outside from DASYLab.

2) DAQBOOK 200 + DBK 42 use not correct internal parameters for sampling rate and blocksize. Please contact your local IOtech dealer for this problem, it's outside from DASYLab.

3) Any other component from used worksheet needs too many time and the DAQBOOK 200 + DBK 42 don't detect an internal FIFO hardware overrun.  Please contact your local IOtech dealer for this problem, it's outside from DASYLab.

Best regards,
MHa

[chassis]

Hi,

Your DaqBook connected to the computer through the Parallel port. In Bios on your computer you must enable the EPP fast mode for parallel port. after this check your setting in the IOtech driver.

Herman.

[CJ_Butler__DASYLab_Pro]

Herman, that would not cause the described problem. If the port were not set up for EPP, he would simply get a Sampling Rate too Fast message, and the measurement would stop.

He has described a possible problem inside of the driver, or with his own computer clock. I think this whole discussion was processed off-line, directly with the hardware technical support. I don't know if it was resolved completely. The problem did not occur with other drivers, but was reproduceable with his configuration.

[chassis]

CJ,

I'm had this problem with delayed PC time in using of same hardware (daqbook 200 + DBK42), and in the the hardware requirement for daqbook 200 wrote about EPP fast mode. It's completely solved this problem in my case.

Herman.

[Cruiser_kidd]

All, The problem I had posted was also described to IOTech who was able to reproduce the Clock Error as well. After some investigation on their part, they said it was a driver problem that would likely not be resolved based on the age of the equipment that I am using. Thanks to all for you responses!!!