Questions regarding temperature controlled setup in Dasylab

[Mr_student]

The reason my responses are not so fast, is because i only have acces to the pc with the software on 2 times a week in a few hours pr day. In these hours i need to make sample tests and do change/fix the problems with the setup.

i have send you some pictures of what you requested. 

The analog input under driver information = AI Channel 0..15 
The analog output from the driver information = AO Channel 0..1 

in Instacal i have put the data rate to 2.5hz but i might need to increase that. 

Regards 
Mr student

[CJ_Butler__DASYLab_Pro]

Please download and enable the latest MCC DASYLab driver, 13.4. You may also need to download and update InstaCal to 6.60

www.mccdaq.com/Software-Downloads

You have configured the Analog Output for N samples, where N=1. This will not work. It needs to be Continuous. Ensure that the Analog Output Measurement setting selects the USB-2408-2AO Software time base. 

[Mr_student]

I got the PID controller to work - by using the settings that you recommeded to me earlier. 

The only problem i got right now with it, is finding the right parameters to use. 
Because i found the right parameteres with out connecting the rest of my channels, but now when i connected the rest of the channels to the setup as well, it changed my scan rate, and i cant change it back because it exceeds the "allowed" scan rate - is there anyway around that ? 

My scan rate before was 2 hz now it doesnt allow me to use more then 0,41..... hz scan rate. 

i dont understand why adding 4 extra channels changes the allowed scan rate ? is it a limitation in the software or the DAQ controller ?.

[CJ_Butler__DASYLab_Pro]

Please read the manual for the USB-2408. The settings in InstaCal per channel determine the maximum sample rate. If you set a channel for 60 hz in InstaCal, it will limit all of the channels. 

There is a table of rates and the effect on sample rates at the back of the manual. 

This is a feature to allow for smoothing of thermocouple readings. You can use an Average module in DASYLab with a moving average to replace the setting in InstaCal - speed up the channels there, and you will get more sample rate in DASYLab. 

[Mr_student]

i did read that, that was also why i increased the data rate of the thermocoupler. 
But from what i understand, i need to do it for all of them to give the "effect" in dasylab ? 
Now i put all of the channels in instacal to 50 hz instead of just only adjusting the one with the thermocoupler on. ( before it was 2,5 )

but When i try to change the scan rate in dasylab it is still restricted to the same value as before ?

About the smoothing module ( moving average filter) im trying to impliment it because it would also help me when i need to do the data processing after. But when i include the module and match the "correct" wires to it, it gives me and error message ( that the blocklength and time doesnt match up ). 

[CJ_Butler__DASYLab_Pro]

According to the table, if all channels are 50 Hz, then the maximum rate is 6 hz for 8 channels. If you need more than 6 Hz, then you must further increase the rate in InstaCal. 

For the Average, you must configure all channels the same -- click the F8 key on the keyboard and it will copy the settings to all activated channels. 

[Mr_student]

so far that would be good enough but i send attached some pictures so you can see it, because i think i did what i was suppose to do to make it "work". 

You see the setup and how i changed the data rate in instacal to 50 hz but ofcause i only changed it on the channels that i use 0-5. 
you see the change i did i dasylab and the error message it gives me. 

[Mr_student]

so far that would be good enough but i send attached some pictures so you can see it, because i think i did what i was suppose to do to make it "work". 

You see the setup and how i changed the data rate in instacal to 50 hz but ofcause i only changed it on the channels that i use 0-5. 
you see the change i did i dasylab and the error message it gives me. 

[Mr_student]

I fixed the problem with the scan rate now, but now my blocklength arent matching up, and it demands to be atleast 2048 for the device. 
With the channels connected at this point the scan rate is 8 hz with the date rate 50 hz selected in instacal. 

Regards -

Mr_student

[CJ_Butler__DASYLab_Pro · Accepted solution]

I think that you need to change the Analog Output - Measurement - Time base to the one that ends in -SW.