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Modbus Monitoring Specifications

The Messenger monitors equipment and devices using Modbus RTU over RS-485 or RS-232.

All values read can be automatically converted into engineering units, compared to user-specified limits (2-high and 2-low) and the web-based back-end alerted immediatly upon a limit violation.

Conditions Monitored
General input conditions
  • 100 Modbus RTU register values
  • GPS coordinates for location (can be removed if not required for the application)
  • General purpose or pulse closure-to-ground inputs
  • Analog input 0-10V (0-20ma or resistive optional)
Internal computations
  • Instantaneous flow, totalized daily flow, total flow from inception
  • Total, Idling and Working fuel used per day
  • Engine statistics (max, min) for a run (Engine On to Engine Off)
  • Engine statistics (max, min) for the day
  • Any Modbus value statistics (max, min) for the day
Reporting values to the web-based back-end
  • Raw value or scaled into engineering units
  • Max, Min over the day
  • Amount of time in a range, up to 4 ranges can be specified per value monitored
  • Number of times moving into a range
  • 2 high and 2 low limits specified per value monitored
  • Report immediately when any limit has been violated
Modbus communications
  • 100 Modbus RTU registers
  • 16- or 32-bit holding, packed digitals, float, or unpacked digitals
  • Data can be raw Modbus or automatically scaled into engineering units
  • Reverse ordering supported
  • Bits can be masked
  • On/Off control supported via Modbus
Serial ports
  • RS232/RS485 for Modbus RTU
  • RS232 for debug or configuration
  • External CDMA or Satellite modems
  • Support OEM-specific communication
Battery backed
  • Real-Time Clock
  • Programming
  • Event log
Communication methods to web-based back-end
  • Wi-Fi
  • CDMA
  • Satellite
  • Serial
  • FCC, PTCRB and ATT approvals for GSM/GPRS end-user applications
  • Operating vibration: exceeds SAE J1455 vibration levels
  • Operating shock: exceeds SAE J1455 shock levels
  • Enclosure: exceeds IP65/NEMA 4X
  • RoHS compliant
Power management
  • Extreme low power mode for battery-powered applications
  • Automatic switch out of low power on: movement, engine on, time
Memory management
  • 512k FLASH for application, loadable OTA or via serial connection
  • 512k low-low power SRAM, battery backed
DIP switches
  • Serial port function - Debug, Other
  • Serial port interface - RS232 or RS485
  • Baud rate
Event logger
  • Last 500 significant events
  • Accessible over-the-air
  • Accessible locally via serial port
  • Battery backed
  • Power modes - off, low, full
  • Cellular/Wireless status and signal strength
  • GPS status
  • CAN status
  • Serial port status
  • OEM specific
General purpose inputs
  • Up to 3 digital (closure to ground) inputs
  • Analog input - voltage, ma or resistive
  • Digital output (closure to ground)
SMS capabiltiy
  • Receive commands for changing configuration
  • Receive commands for over-the-air direct communications with internal menuing system
  • On-demand reporting of values
  • OEM specific
Physical Characteristics
  • 3.25" x 3.95"
  • Operating power: 8-32VDC
  • Sleep mode - less than 6 ma @ 12VDC
  • Monitoring mode - 110ma @ 12VDC
  • GPRS transmit mode - 600ma peak @ 12VDC
  • Industrial temperature range -40 to +85C
  • Watertight industrial enclosure