I have a DT800 permanent linked to my PC by RS232 cables (COM1). I use DeLOAD to periodically and automatically unload the logged data.

Now I improved the monitoring system and I connected to my PC an independent accelerometer (connected at COM2). I have access to stream data of the accelerometer in a LabVIEW program.

I would like to be able to change the sample rate of the DT (1 Hz to 10 Hz) by a trigger provided by the accelerometer readings. After detect an event at the accelerometer (in a simple threshold algorithm programmed in LabVIEW), I would like to change the DT sample rate as soon as possible to minimize the lost data after event detection.

What is the best and fastest way to send the trigger command to the DT? Per example, have the DT always connected, send the command via LabVIEW DT drivers, DeLOAD command, digital channel trigger, serial cable, or other. What do you suggest me?

Thanks,
FG

Good morning FG,

All you need to do is send the schedule definition with the new rate. For example, if your DT800 is running the code:

BEGIN RA1S 1V END

Then sending RA100T will change the speed to 10 Hz and sending RA1S will change it back again.

If you are worrying about speed then why not have the DT800 change the speed itself, e.g.

BEGIN
RA1S
1V(=1CV) 'Read a Voltage
ALARM1(1V>100)"High Voltage"{RA100T} 'Change the sample speed
ALARM2(1V<100)"Low Voltage"{RA1S} 'Change back again
END

Cheers,
Roger

If I understood correctly, the DT800 hasn't got the "access" to the accelerometer, so adaptive schedule as suggested by Roger isn't applicable.

I think that, if you have the DT800 permanently connected to the same PC with LabView, the fastest way is that LabView sends out serial commands (e.g. RA1S, RA100T as suggested by Roger) to change the DT800 acq. rate.

Regards

Thanks Roger and teo.

Effectively teo was correct and i'm not access to the accelerometer signal in the dataTaker unit.

Like suggested, I adopted the solution of send commands by LabVIEW programming (RA1S and RA100T). It works OK and it is fast enough to the intent.

Thanks.
FG