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NON LINEAR ANALOG INPUT DRIVER SETUP
To setup an analog sensor in DashDAQ (sensor pre-wired to accessory cable assumed, see section 0):
1. From the DashDAQ Main Menu tap on [Setup], then [Devices], then [Manager].
2. Tap on an empty slot and tap [Change].
3. Use the [<] or [>] buttons at the top to find the “Other” heading. Tap on [Non Linear Analog Input] to highlight and tap [Save].
4. Now notice which port is specified on the change device screen. The black box next to the [Port] button contains a sensor
number that should correspond to the number of the Analog Input that the sensor is connected to. If it does not tap the [Port]
button once for the other analog input.
5. Tap [Save]. The analog sensor is now specified as an input in the Device Manager and can be assigned to any gauge to be
viewed as voltage. To understand how to scale the signal to a specific unit see the next section (Section 0).
NON LINEAR ANALOG INPUT CONFIGURATION
The Non Linear Driver is configured by the use of a configuration file. The nature of the configuration file will be covered in the next
section. To configure the driver:
1. From the DashDAQ Main Menu tap on [Setup], then [Devices], then [Parameters].
2. Tap on the [<] or [>] until the letter for the Non Linear Driver being configured is shown.
3. Tap on a parameter to highlight it and tap on [Change] to change that parameter. The parameter meanings are as follows:
• Conversion Data Filename: This is the name of the configuration file name. By default the file is named either
“analog1.config” or “analog2.config”, depending on which port this driver is configured for. The file name root can be
anything, but the suffix must be .config in order to install it.
• Signal Name: This is the name that will show up on the gauge.
• Units Name: This is the physcial units type (degC, kPA, PSI, etc). This will be displayed on the gauge if the gauge has
enough room to display it in full. This is also used to do automatic English <-> Metric conversion. The units name
must be exactly match one of DashDAQ’s standard units values in order for English <-> Metric conversion to work
properly. The current units conversion set is shown in Appendix B.
NON LINEAR ANALOG INPUT DRIVER CONFIGURATION FILE
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:
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