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Trimble Copernicus GPS Receiver

Internal to Raveon’s M7 series of GPS transponders is a GPS receiver module made by Trimble.  It is their Copernicus II GPS receiver module.  Many of the M7’s performance specifications are driven by the use of this receiver module.  The Copernicus II is ideally suited for vehicle tracking systems, AVL, asset tracking, and personal location.   Details of the module are available on Trimble’s website at: http://www.trimble.com/embeddedsystems/copernicus.aspx?dtID=overview 

The following is a summery of the Copernicus GPS modules features and performance:

Overview

Trimble’s Copernicus® GPS receiver delivers proven performance and Trimble quality for a new generation of position-enabled products. It features the Trimble revolutionary TrimCore™ software technology for extremely fast startup times and high performance in foliage canopy and urban canyon environments. The Copernicus module is a complete 12-channel SBAS (which includes WAAS, EGNOS) capable GPS receiver in a thumbnail-sized module. Each module is manufactured and factory tested to Trimble’s highest quality standards.

Key Features:

  • 2.54 mm T x 19 mm W x 19 mm L
  • 94 mW typical continuous tracking
  • Supports SBAS (WAAS, EGNOS)
  • Active or passive antennas
  • NMEA, TSIP, TAIP protocols
  • RoHS-Compliant (Pb-free)

The sensitive Copernicus II GPS receiver can autonomously acquire GPS satellite signals and quickly generate reliable position fixes in extremely challenging environments and under poor signal conditions The unit also accepts aided GPS (A-GPS) data for faster startups in very weak conditions.  The Copernicus II GPS module is a complete drop-in, ready-to-go receiver that provides position, velocity, and time data in a user’s choice of three protocols Trimble’s powerful TSIP protocol offers complete control over receiver operation and provides detailed satellite information.

PERFORMANCE SPECIFICATIONS

Accuracy (24 hr static)

  • Horizontal. <2.5 m 50%, <5 m 90%
  • SBAS. <2.0 m 50%, <4 m 90%
  • Altitude. <5 m 50%, <8 m 90%
  • SBAS. <3 m 50%, <5 m 90%
  • Velocity. 0.06 m/sec
  • Static PPs. +/- 60ns RMS
  • PPS (Stationary Mode “indoor” @ -145dBm). +/-350ns

Acquisition (Autonomous, -130dBm, 50%)

  • Reacquisition. 2 s
  • Hot Start. 3 s
  • Hot Start without battery backup. 8 s*
  • Warm Start. 35 s
  • Cold Start. 38 s

Sensitivity (unaided)

  • Tracking . -160 dBm
  • Acquisition. -146 dBm
  • Receiver Dynamics. 2G

TDMA Time Slots

M7 Firmware Updating

Overview

This Technical Brief describes how to upload firmware into the RV-M7 transceiver.  The RV-M7 series transceivers utilize a Phillips ARM-based Microprocessor with internal FLASH memory.

All RV-M7-GX series transceiver use an LPC2136 processor, which has 256kB of flash memory.

Phillips Semiconductor provides a utility to upload firmware into the microprocessor. Their program is called “LPC2000 Flash Utility” This utility may be used in the field to upload new firmware into the RV-M7 series transceivers.

Firmware updating information and software revision implications is also available in Application Note AN136 which is in .pdf form. 

Procedure

1.0 Uploading Firmware

1. Extract the .zip files if the firmware update was supplied in .zip format.

2. Open the Philips Flash Utility Installation.exe file inside the LPC21xx folder. The version must be V2.2.3 or higher. Version 2.2.3 is available <here>. Walk through the installation steps to install the Philips Flash Utility program. The Utility program should open when the installation is complete. The Utility program window is shown below.

Philips Flash Utility

3. Select the appropriate COM port from the Connected To Port pull-down menu.

4. Set the baud rate to 19200 from the Use Baud Rate pull-down menu.

5. Set the XTAL Freq (kHz) to 20000.

6. Select the appropriate file to upload to the modem. The file name will end in a .hex extension.

7. Remove the four Phillips panhead screws securing the modem’s rear panel to the housing. You don’t need to disconnect the SMA GPS cable from the rear panel.

8. Carefully remove the rear panel from the modem housing. The internal SMA GPS cable has a 2” service loop to allow access to the modem’s CONFIG button. The CONFIG button location is shown below.

configbutton

9. Set a DC power supply for +12VDC. Set the power supply output OFF.

10. Connect the PC serial port to the modem’s DB9 front panel connector.

11. Connect the modem’s green 2-pin power connector to the power supply.

12. Press and hold the modem CONFIG button. Set the power supply output to ON, wait approximately 2 seconds, and release the CONFIG button. If these steps were performed correctly the modem’s current draw should be approximately 30mA.

13. Press the Read Device ID button on the Philips Utility program window to establish communication with the modem. A reset message saying “Please reset your LPC2000 board now and then press OK!” will appear. DO NOT RESET POWER TO THE MODEM. Press the OK button. A “Read Part ID Successfully” message will appear in the lower left corner of the Flash Utility program window.

Note: When the Read Device ID button is pressed the Utility program may display a “Cannot communicate with test board!” message. Disregard this message. Press the OK button and press the Read Device ID button again to establish communications with the modem.

14. Press the Upload to Flash button on the Philips Utility program window to upload the 2F700GXB5.hex file to the modem’s flash memory. The Utility program will display a “File Upload Successfully Completed” in the lower left corner when the file upload is completed.

15. Repeat steps 7 through 14 for any additional units.

 

2.0 Configuring the Modem

1. Close the Philips Flash Utility program.

2. Open a terminal program with port settings of 8 data bits, no parity, 1 stop bit, and flow control off. The bps setting will depend on the previous modem configuration of the ATBD setting. For modem ID: 0001 and 0002 set the bps setting to 38400 and for modem ID: 0003 set the bps setting to 4800.

3. Set a DC power supply for +12VDC.

4. Connect the PC serial port to the modem’s DB9 front panel connector.

5. Connect the modem’s green 2-pin power connector to the power supply.

6. Type “+++” on the terminal program to enter the modem’s configuration mode.

7. Configure the product per the user manual and instructions in AN136.

3. Firmware Versions

In most cases, the firmware in an M7 must be udated at the factory because updated radio modems should be completely re-calibrated and all parameters initialized.  But, in certain cases it may be possible to perform the upgrade in the field.  AN136 lists the parameters which must be re-calibrated or initialed when doing a firmware upgrade. 

Below are links to firmware for the M7 data radio modem. 

Revsion C1 hex file

Revision C1 zipped

M7 I/O Connections

The M7’s I/O Connector

On the front of the M7 series of GPS transponders, is an Input / output (I/O) connector used to configure the unit.  This I/O connector supports RS232 serial data (422 optionally), as well as digital input and output.

The RS232 9-pin serial I/O connector is a female 9-pin D-subminiature connector having the following pins configuration. It is pinned out so that it may be plugged directly into a computer or PC’s 9-pin COM port.

db9

DB9 Female I/O connector

Front-view of DB-9 connector on modem (female)

Pin

Name

Dir

Function

Level / Specification

1

CD

out

Carrier detect

If enabled, indicates presence of carrier. Logical 0 (+ voltage on RS-232) means carrier is present. If disabled, it is asserted (0) whenever the modem is operational, and not in the configuration mode. It will be a 1 when the modem is in the configuration mode.

2

RxD

out

Receive data

Data out of the modem.

3

TxD

in

Transmit data
or
IN2

Data into the modem.

Also used as digital input IN2 for exception reporting. GND or floating for a 0, >3V for digital 1. If enabled for digital inputs, the serial data entering this pin is ignored (except in the command mode). Use the TRIGBITS command to set which bits are used as inputs.

4

DTR

in

Data terminal ready
or
IN0

Normally ignored by the RV-M7 modem.  May control the power-state of the modem in low-power mode if this feature is enabled.

Also used as digital input IN0 for exception reporting. GND or floating for a 0, >3V for digital 1. Use the TRIGBITS command to set which bits are used as inputs.

5

GND

 

Ground connection

Signal and power ground

6

DSR

out

Data Set Ready

Normally is set to 0 when modem is powered on and running. Modem sets to a 1 when in low-power mode.  

7

RTS

in

Request to send
or
IN1

Used to stop/start the flow of data coming out of the modem TxD pin. 0 = OK to send, 1 = don’t send. Leave disconnected if not used.

Also used as digital input IN1 for exception reporting. GND or floating for a 0, >3V for digital 1. Use the TRIGBITS command to set which bits are used as inputs.

8

CTS

out

Clear to send

Used to stop the flow of data going into the RxD pin from the device connected to the RV-M7. 0 = OK to send, 1 = don’t send. If the RV-M7 cannot accept more data, it will negate this signal (set to a 1).

9

Power

In/out

DC power (not ring signal)

User may supply the DC power to the modem on this pin.

Note: RS-232 signals use positive and negative voltages to represent digital 1s and 0s. A positive voltage is a 0, and a negative voltage is a digital 1.

This I/O pin-out allows the M7 to be directly plugged into a PC computer’s 9-pin serial port using a conventional 9-pin RS-232 serial cable. To connect it to a modem, or peripheral that has a serial port, you will need a “null-modem” cable.

Null Modem Cables

Sometimes, a “Null Modem” cable may be required to connect the M7 modem to another device. The specific connections are very dependent upon the type of hardware and handshaking used, but the following sections should help in configuring a null-modem cable.

How to use the handshaking lines in a null modem configuration? The simplest way is to don’t use them at all. In that situation, only the data lines and signal ground are cross connected in the null modem communication cable. All other pins have no connection. An example of such a null modem cable without handshaking can be seen in the figure below.

nullmodem

Simple Null-Modem Wiring Diagram

(Same wiring for male-to-male or female-to-femal cable)

Connector 1

Connector 2

Function

2

3

Rx

 

Tx

3

2

Tx

 

Rx

5

5

Signal ground

If you are connecting your M7 to a Lowrance or Garmin GPS display, then you will need a null-modem cable to connect the M7 to the display. Lowrance provides a serial cable for its GPSs with “pigtail” wires, so you can solder your own DB9 male connector to it, and plug the Lowrance directly into the M7.

To connect a Garmin GPS, use a null-modem cable to connect it to the M7, or the supplied Garmin serial cable and a “Null Modem Adaptor”.

Digital Inputs

The M7 GX Transponder has 3 digital inputs, called Trigger Bits. Trigger Bits are digital inputs that trigger the M7 GX to report its position and status. Normally these inputs are used for RS-232 signals, but they may be used for general-purpose digital inputs. The M7 GX may be configured to trigger a position/status report based upon the digital input bits state.

Important: If the digital input function is not needed, the TRIGBITS setting must be set to 0. This is the factory-default setting, and unexpected transmission may happen if the digital inputs are enabled and not used.

The status of all digital inputs is transmitted every time the unit reports its position.  This is not dependent upon how the TRIGBITS paramter is set. Each transmission, all digital input status is sent.

Starting with firmware version C2 and higher, the digital inputs have “memory” if they are enabled with the TRIGBITS command.  If you enable a bit or bits with the TRIGBITS command so that it triggers high, then the M7 will remember that a bit goes high if it does so, even momentarily.  For example, if a TRIGBIT bit goes high and then quickly goes back low, the M7 will remember this, and the next time it reports its position, will report the bit as “High”, even if it is low. Subsequent position transmissions will report it low, until it goes high again. If a bit is not configured as a TRIGBIT, then the M7 will report the state of the bit at the moment the GPS position is transmitted.

If you are not using digital inputs to initiate a transmission, the TRIGBITS should be set to 0. (TRIGBITS 0 command)

If the RV-M7 GX was configured to transmit less-often when it is not moving, activation of the digital inputs will override this causing the unit to report at the interval programmed with the TXRATE command. The digital inputs may be configured to be active high, active low, or active on a change in state. The following table lists the available digital inputs on the standard RV-M7 GX:

RS-232 Pin

Function

4 – DTR

Input 0

7 – RTS

Input 1

3 – TXD

Input 2

5 – Ground

GND

 There are 3 commands that must be configured to use the digital inputs:

TRIGBITS x This command enables or disables individual bits for use as input triggers.

TRIGPOL x Sets the polarity of the input. 0=active high, 1=inverted, active low.

TRIGEX x Sets which bits are used to report on exception. Exception reporting is when a position/status report is generated when an input changes either low-to-high or high-to-low.

The xx parameter is the hex binary representation of the bits. Refer to the following table to see the value for x.

IN 2
(TXD)

IN 1
(RTS)

IN 0
(DTR)

Hexadecimal Representation

0

0

0

0

0

0

1

1

0

1

0

2

0

1

1

3

1

0

0

4

1

0

1

5

1

1

0

6

1

1

1

7

For example, to enable bits 0 and 2 (DTR and TxD pins) to be used as digital input, issue the following commend:

TRIGBITS 5

If the bits are to be normally active high, then the polarity must be set to 0 (TRIGPOL 0 command). To set bit 0 so that it is inverted (active low), use the following command:

TRIGPOL 1

This will cause the unit to transmit when bit 0 (DTR pin) is low.

To enable exception reporting, that is transmit when a pin changes from low-to-high or high-to-low, use the TRIGEX command. When TRIGEX is 0, all inputs are active either high or low. When a bit is set to 1 in TRIGEX, then that bit will cause the unit to transmit position/status anytime it changes state.

For example, to configure the unit to transmit position when bit 0 changes state, issue these commands:

TRIGBITS 1 (enables bit 0)

TRIGEX 1 (configures bit 0 for exception reporting)

To configure all bits to be used to report when they change, issue these commands:

TRIGBITS 7 (enables bit 0, 1 and 2)

TRIGEX 7 (configures bit 0, 1, and 2 for exception reporting)

To configure bit 0 to be used to report when it changes, bit 1 to cause a report when it goes low, and disable bit 2, use these commands.

TRIGBITS 3 (enables bit 0 and 1, disable 2)

TRIGEX 1 (configures bit 0 for exception reporting)

TRIGPOL 2 (configures bit 1 for active-low reporting)