Test and Measurement Forum

File location issue for .psc

Post all DrDAQ questions here

File location issue for .psc

Postby Hominid » Wed Jul 04, 2018 4:48 pm

Does anyone have experience using a scaling file for a temp/resistance table? The file's location doesn't seem to be documented in the user guide... that, along with the location of the plw.ini file as well. I have version 6 of Picolog installed, and a Windows search comes up with nothing. Is the documentation out of date perhaps?

Quote from page 122 of the Picolog User Manual: "PicoLog and other Pico software products are provided with a set of .psc files that contain scaling information on a wide range of sensors."

I see no .psc files anywhere...
Hominid
Newbie
 
Posts: 0
Joined: Thu Jun 28, 2018 6:13 pm

Re: File location issue for .psc

Postby Martyn » Wed Jul 04, 2018 9:07 pm

The PicoLog User manual is for version 5 of the software and the files would be in the installation directory. PicoLog 6 is new, and a completely different piece of software, so I will need to check on how scaling files can be used as it hasn't been asked before.
Martyn
Technical Support Manager
Martyn
Site Admin
Site Admin
 
Posts: 3155
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: File location issue for .psc

Postby Martyn » Thu Jul 05, 2018 5:35 am

For the DrDAQ you can create a dds file as shown in "Section 2.10.5 USB DrDAQ scaling files (.DDS)" of the DrDAQ User Guide and put this with the usbdrdaq.dll in "C:\Program Files\Pico Technology\PicoLog 6\resources"
Martyn
Technical Support Manager
Martyn
Site Admin
Site Admin
 
Posts: 3155
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: File location issue for .psc

Postby Hominid » Fri Jul 06, 2018 10:14 pm

Martyn wrote:For the DrDAQ you can create a dds file as shown in "Section 2.10.5 USB DrDAQ scaling files (.DDS)" of the DrDAQ User Guide and put this with the usbdrdaq.dll in "C:\Program Files\Pico Technology\PicoLog 6\resources"


There's no explanation about how to enter temp / resistance values, only volts. Do I have to figure out what the volts are for each resistance value? Perhaps an example table would be helpful... what our project is using is a 4kohm thermister with a non-linear curve. Here's a snippet:


Ohms Temp
~~~~~ ~~~~
11594.72 0
9243.6 5
7422.72 10
6001.64 15
4884.44 20
4000 25
3295.16 30
2729.88 35
2273.76 40

How do I enter that into this .DDS file?

Thanks in advance...
Hominid
Newbie
 
Posts: 0
Joined: Thu Jun 28, 2018 6:13 pm

Re: File location issue for .psc

Postby Martyn » Mon Jul 09, 2018 7:57 am

The Signal Input channel has 100 kΩ pull-up resistors to 2.5 V, so with the resistance of the RTD from the signal input to ground you have a voltage divider which will map voltage to temperature. This information can then be used in a .DDS file.
Martyn
Technical Support Manager
Martyn
Site Admin
Site Admin
 
Posts: 3155
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots


Return to USB DrDAQ

Who is online

Users browsing this forum: No registered users and 0 guests