Digital Inputs Introduction
Written by Matthew Clark-Massera
Updated at August 1st, 2024
Table of Contents
Applies to:
| Device | Firmware Version |
| Dart3-2G, Dart2-4G, Dart3-4G, Dart3-4G Bluetooth® and Dart3 Global Bluetooth® | All Versions |
| G120-2G and G120-4G | All Versions |
| G150-Global | All Versions |
| G70-2G, G70-4G and G70-4G Bluetooth® | All Versions |
| Hawk 4G (see Hawk Digital Inputs) | All Versions |
The wired devices have both an Ignition Digital Input along with Digital Inputs with configurable pull up/pull down parameters.
These inputs detect the voltage at the input, check it against the thresholds, and then record the digital input as on "1" or off "0". This can be used to determine the state of an asset, for example:
- Door open/close
- Ignition on/off
- Pump on/off
- Button presses
- Pulse counting
This article provides general information about Digital Inputs on the wired devices. Specific set up examples/wiring guides can be found in subsequent articles.
| Device | Ignition Input Count | Digital Input Count |
| Dart3 series | 1 | 3 |
| G120 | 1 | 6 |
| G150 | 1 | 4 |
| G70 series | 1 | 3 |
Digital Input Specs
- Input voltage range = 0 - 48V. This can technically be exceeded without damaging the device, but the input will not work properly outside of this range.
- On/Off Thresholds
- Pull Up Enabled
- Input registers low/off below 0.4V
- High/On above 1.9V
- Pull down enabled
- Registers low/off below 0.8V
- High/On above 2.2V
- Pull Up Enabled
Bias Resistors
The wired devices have a configurable 'Active Level' and Bias Resistor.
- The Active Level determines the physical line level (high or low) at which the input is considered on.
- The Bias Resistor essentially determines the state of the input when nothing is connected to the input. Since often we would leave them disconnected, or 'open circuit' meaning the state isn't well defined. The bias resistor handles this.
There are 3 options:
- Pull up: pull the input high
- Pull down: pull the input low
- Disable: do not bias the input
These options are useful when one of the states being read is open-circuit (disconnected/high impedance). In this case, enable the bias resistor setting in the opposite state to the level being switched to. This is commonly used when working with an "open collector" output. The pull up/down is a "weak" pull up/down.
Results of different configurations.
| Bias Resistor | Active Level | Input | Result |
|---|---|---|---|
| Pull Down | High | Low | Inactive |
| High | Active | High | Active |
| Pull Down | Low | Low | Active |
| High | Inactive | High | Inactive |
| Pull Up | High | Low | Inactive |
| High | Active | High | Active |
| Pull Up | Low | Low | Active |
| High | Inactive | High | Inactive |
Setting Up a Digital Input
Dart3
To set up either Digital Input 1, 2 or 3, you will need to use the corresponding wires. (See DART3 12-wire Harness Definition)
- Digital Input 1 = PINK
- Digital Input 2 = BLUE
- Digital Input 3* = GREEN
*Digital Input 3 is shared with one of the Driver ID lines, so DI3 cannot be used at the same time as a DM RFID reader, or Wiegand Reader.
Then we can add the corresponding parameter tab to apply the right settings.
Function - Either Digital Input or Pulse Counting.
Digital Input - The virtual input number that you want it mapped to.
Bias Resistor and Active Level - See table above.
Log/Upload on Active - By default, the device will only log a record when the input changes. It is not immediately uploaded. In most cases we want to turn this on. So set Upload on Active/Inactive to Yes
Buzzing Parameters - We can optionally have any buzzers connected to notify us that the input is on/off.
Emergency Uploads - A device can be set to not upload in certain areas. This can be set up as part of Geofence Downloads to Device. If the Emergency Uploads is set to Yes, then the device will upload even in a no comms zone.
Config 1 - Debounce Time. By default, the input must stay on continuously for 1000ms = 1sec for the device to register it as on and send an update to the server.
Digital Input 3
To use Digital Input 3, set the 4 Wire Plug Function to iButton/Digital Input 3
G120
The following pins represent the Digital Inputs on the G120
Digital Input 1: Pin 16 - Pink
Digital Input 2: Pin 17 - Blue
Digital Input 3: Pin 18 - Green/Black
Digital Input 4: Pin 19 - Brown
Digital Input 5: Pin 4 - Brown/Blue
Digital Input 6: Pin 5 - Violet/Red
Please see G120 Harness Definition for wire colour information.
To set up a digital input, we first need to add the corresponding Digital Input parameter tab.
Function - Either Digital Input or Pulse Counting.
Digital Input - The virtual input number that you want it mapped to.
Bias Resistor and Active Level - See table above.
Log/Upload on Active - By default, the device will only log a record when the input changes. It is not immediately uploaded. In most cases we want to turn this on. So set Upload on Active/Inactive to Yes
Buzzing Parameters - We can optionally have any buzzers connected to notify us that the input is on/off.
Emergency Uploads - A device can be set to not upload in certain areas. This can be set up as part of Geofence Downloads to Device. If the Emergency Uploads is set to Yes, then the device will upload even in a no comms zone.
Config 1 - Debounce Time. By default, the input must stay on continuously for 1000ms = 1sec for the device to register it as on and send an update to the server.
G150
The following pins represent the Digital Inputs on the G150
Digital Input 1: Harness 1 Pin 4 - Blue
Digital Input 2: Harness 2 Pin 1 - Red
Digital Input 3: Harness 2 Pin 2 - Black
Digital Input 4: Harness 2 Pin 3 - White
Please see G150 Harness Definition for wire colour information.
To set up a digital input, we first need to add the corresponding Digital Input parameter tab.
Function - Either Digital Input or Pulse Counting.
Digital Input - The virtual input number that you want it mapped to.
Bias Resistor and Active Level - See table above.
Log/Upload on Active - By default, the device will only log a record when the input changes. It is not immediately uploaded. In most cases we want to turn this on. So set Upload on Active/Inactive to Yes
Buzzing Parameters - We can optionally have any buzzers connected to notify us that the input is on/off.
Emergency Uploads - A device can be set to not upload in certain areas. This can be set up as part of Geofence Downloads to Device. If the Emergency Uploads is set to Yes, then the device will upload even in a no comms zone.
Config 1 - Debounce Time. By default, the input must stay on continuously for 1000ms = 1sec for the device to register it as on and send an update to the server.
G70
To set up either Digital Input 1 or 2 you will need to use the corresponding wires. See G70 Harness Definition
- Digital Input 1 = BLUE
- Digital Input 2 = ORANGE
-
Digital Input 3* = PURPLE
*Digital Input 3 is shared with one of the Driver ID lines, so DI3 cannot be used at the same time as a DM RFID reader, or Wiegand Reader.
Then we can add the corresponding parameter tab to apply the right settings.
Function - Either Digital Input or Pulse Counting.
Digital Input - The virtual input number that you want it mapped to.
Bias Resistor and Active Level - See table above.
Log/Upload on Active - By default, the device will only log a record when the input changes. It is not immediately uploaded. In most cases we want to turn this on. So set Upload on Active/Inactive to Yes
Buzzing Parameters - We can optionally have any buzzers connected to notify us that the input is on/off.
Emergency Uploads - A device can be set to not upload in certain areas. This can be set up as part of Geofence Downloads to Device. If the Emergency Uploads is set to Yes, then the device will upload even in a no comms zone.
Config 1 - Debounce Time. By default, the input must stay on continuously for 1000ms = 1sec for the device to register it as on and send an update to the server.Tab Body
Digital Input 3
To use Digital Input 3, set the Driver ID Function to iButton/Digital Input 3"
Buzz on Active/Inactive
We can configure the wired device to sound any connected buzzers, or flash an LED, when an input is active/on or inactive/off.
This can be very useful for providing feedback to drivers/operators, for example:
- Sounding a buzzer when a seatbelt is undone or a tailgate is open.
- Sounding a buzzer when a duress button has been pressed, to provide feedback that it was registered (note, this doesn't confirm that it has been received by the server). This can also help prevent false alerts as drivers are notified of accidental presses and can contact response teams.
We can configure buzzing with these parameters. Setting the count to 255 enables continuous buzzing, for the entire time an input is on/off.
Example - 3 beeps when an input goes active.
This would result in the below when the input goes active:
Buzzer on 20ms -> off 20ms -> on 20ms -> off 20ms -> on 20ms -> off 20ms
Example - Continuous buzzing when an input is on, long buzzes (500ms on/off)
Buzz only when the ignition is on
We may want to set up the wired device to buzz when an input is active, and the ignition is on. i.e. we want to buzz if the tailgate is left open and the engine is running. We can solve this using the Input Monitor