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TTU-2900 Hardware & Installation Guide - PULS Wiki
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A/D 6: GPS Antenna Monitor
A/D 7: µP Temperature (internal use only)
A/D 8: Vref
A/D 9: Battery
Outputs:
Output 0: Out-0
Output 1: Out-1
Output 2: Out-2
Internal Outputs
Output 7: Pwr Switch
Output 8: Chrg Disable
Output 13: 12Vout Enable
Output 14: Internal Buzzer (Optional)
3.4.1
Internal Buzzer
The TTU-2900
™
supports an internal buzzer on output 14. Buzzer volume can be set from 0 to 100% volume and can be turned on and off with
the corresponding AT commands.
3.4.2
3-Axis Accelerometer Input
The TTU-2900
™
supports an internal 3 Axis Precision Accelerometer as one of its discreet inputs. When the LMU is moved in any direction, the
associated input will be in the High state. If the LMU’s accelerometer does not detect motion, then the input will be in the Low state. No external
connections are required for this functionality to be operational.
3.4.3
Ignition and Inputs
The TTU-2900
™
provides up to 5 inputs. These inputs are protected from typical vehicle transients and can be directly connected to most vehicle
level logical inputs from 0 volts up to the vehicle power input level (typically 12 VDC). One of these inputs is dedicated to sensing the vehicle’s
ignition status to provide for flexible power management. The other 4 inputs may be used to sense vehicle inputs such as cooling unit operation, a
hidden driver “Panic” switch, taxi on-duty/off-duty meter status or many others.
The ignition input is pulled to ground through the 268k resistance, where the other inputs can be configured to be normally High (i.e. pulled to
+6v through a 210k resistor) or Low (i.e. pulled to ground through a 43k resistor). The diagrams below show how to connect the inputs in both a
high- and low-biased configuration:
(at$app param 1078,0,50 // set the buzzer volume to 50% (range 0-100)
at$app peg action 8 14 // turn buzzer on
at$app peg action 9 14 // turn buzzer off)
