Drew Technologies DASHDAQ-XL - Manual (Page 36)

36
The analog inputs of DashDAQ have 10 bit A/D converters. This means that there’s 1024 discrete readings possible on each A/D input.
The actual input measuring range for the A/D converter is 0 to 5.035V in 1023 steps, with the 1024
th
step being anything over 5.035V, so
each step is (5.035/1023), or approximately 0.00492 volts.
The configuration file consists of 1024 ascii numbers separated by any non numeric character except ‘.’, ‘+’, or ‘-‘. Each number in the
configuration file is what will be displayed for that voltage step on the input. For example, if you created a file that had the ascii
numbers 1 to 1024 in it separated by spaces, for voltage inputs from 0-0.00492V the DashDAQ would display 1, for 0.00492-0.00984V
the DashDAQ would display 2, continuing to 5.030V to 5.035V would display 1023, and finally 5.035V or greater would display 1024.
Given the DashDAQ input impedance of 24.7 Kohm and knowing the resistance or voltage output of a given sensor over the range that
is to be measured, it’s possible to create a configuration file for most resistive and amplified sensor types. The sensor setup options and
calculations involved in creating the file are beyond the scope of this manual and will be covered in a separate application note.
Once an appropriate configuration file has been generated, it must be installed on DashDAQ from a SD card to be used. To install the
configuration file:
1. On a PC, insert a SD card into a card reader/writer in the PC, create a subdirectory called “transfer” on the SD card, and copy
the configuration file to the transfer directory on the SD card. NOTE: the configuration file name must end in “.config”.
2. Place the SD card into a powered off DashDAQ and then power it up.
3. From the DashDAQ Main Menu, tap on [Setup], then tap on [Memory Card], then tap on [Install], then tap on [Config File].
4. The configuration file should be shown on the Install screen. Highlight the configuration file by tapping on it and tap OK. A
popup should indicate the file was installed successfully. Tap OK on the popup.
5. Configure the driver to use the installed file as described in the previous section.
UPDATING DASHDAQ
DashDAQ’s software is field updateable. The software necessary to update the DashDAQ is on the included CD.
INSTALL THE DASHDAQ RECOVERY TOOL
DashDAQ comes with a CD that contains the DashDAQ update software. This auto run website will appear after inserting the CD in a
computer:
Screen visible after inserting CD
1. Click on number 3, “DashDAQ Recovery Tool”. This screen appears: