AccuGrade® Version 11 Compaction GPS Mapping and Measurement System Caterpillar

The AccuGrade System must use a radio that is compatible with the radio that is on the base station. Caterpillar currently offers the CR9xx and TC450C for the AccuGrade System. These radios require Trimble infrastructure radios for compatibility.

For sites that are using "non-Trimble" infrastructure, a Customer Supplied Radio may be used with the System. However, a Customer Supplied Radio will need to be configured for use with the System. This section outlines the wiring issues that must be addressed in order to provide communication with the System.

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NOTICE
Caterpillar makes no claim to compatibility with all radios. Additionally, Caterpillar assumes no responsibility for the performance of a system that is integrated with a Customer Supplied Radio.

The following recommendations must be considered when a Customer Supplied Radio is installed:

• 18-gauge wire is recommended for all lines. Avoid any wire with a narrower gauge.

• Machine pinouts may vary. Consult the Electrical Schematic for each machine to determine the correct pinouts.

• These instructions do not address any unique power requirements that may apply to an individual Customer Supplied Radio.

Power to a Customer Supplied Radio is provided through the AccuGrade harness at a nominal 24 VDC (15 amp max). Power may vary from 22 - 28 VDC during radio operation. If regulated power is required by the Customer Supplied Radio, it is the responsibility of the customer to provide a power converter to the radio. Additionally, it is the responsibility of the customer to wire the power converter to the radio.

1. Locate the schematic for the connector for your Customer Supplied Radio.

   Refer to the owner's manual or the documentation from the manufacturer.

   1. Verify that 24 VDC nominal power is acceptable.

      Note: If there are any limitations on input power, find a suitable converter. The converter should be wired between the AccuGrade connection and the connection for the Customer Supplied Radio.

   2. Find the required power and communications pins on the radio.

      These pins may vary for each Customer Supplied Radio. The pins that are listed below are the minimum that are required:

      • + BAT

      • GRND

      • TX

      • RX

2. Locate the electrical schematic for the AccuGrade System and the specific Caterpillar machine. Schematics are available at SISWeb.

   1. Find the 8-pin connector for the GPS radio.

   2. Trace back from the 8-pin connector to the 12-pin connector.

      Note the pin number for the following connections:

      • + PWR

      • GRND

      • COM 2 TX

      • COM 2 RX

3. Wire the new cable.

   Use the pinouts that are noted in Steps 1 and 2.

Illustration 1	g01259989

Customer Supplied Radio Example

Field Conditions

• Existing AccuGrade compatible GPS base station

• Customer Supplied Radio at the GPS base station

Required

• Create a cable that connects a compatible Customer Supplied Radio to the AccuGrade System.

1. Can the Customer Supplied Radio communicate CMR data over RS-232.

   Yes - The Customer Supplied Radio is compatible with the AccuGrade System.

   No - The Customer Supplied Radio is not compatible with the AccuGrade System.

2. Will the machine radio operate within 9-32 VDC.

   Note: Verify that all necessary connections can operate at machine voltages.

   Answer - By looking in the radio documentation, found that the radio can run on 9-32 VDC. In order for the radio to function, the DTR line needs to be tied high. The line has a limitation of 25 VDC.

   Solution - Use a DC to DC power Converter to step the voltage down to 12 VDC.

3. Make all of the necessary connections. Use the information from the manufacture of the radio.
   • Power

   • Ground

   • TXD

   • RXD

   • DTR

   Note: DTR is required by the radio in this example in order to make the radio active.

4. Use the referenced pinouts for the machine harness. Wire the following for the machine harness connector.
   • Power

   • Ground

   • COM2 TXD

   • COM2 RXD

5. Configure the machine radio and the AccuGrade System to communicate over RS232.

   ReferenceReference Systems Operation, "Radio Utility"

   1. Ensure that the values in the "Customer Supplied Radio" match the values in the Display.

      Default Settings For The Display

      Baud rate ... 38400

      Data Bits ... 8 (Fixed setting on Display)

      Parity ... None

      Stop Bits ... 1 (Fixed setting on Display)

6. Verify that the "over-the-air data/communications" rate is set to the same value in both the radio at the base station and the radio on the machine.

   The optimal rate may vary depending on the radio. The typical rate is between 4800 bps and 38400 bps. The same rate must be set in both the base radio and the machine radio. If the same rate is set, you may proceed. Set the rates of both radios to the same value. Use the radio configuration software.

7. Connect the new adapter harness to the main harness.

8. Connect the new adapter harness to the machine radio.

9. Apply power to the system. Verify that the radio can communicate with the base station.

   Use the Display in order to check the data link. The link should be increasing for the integrity.

Customer Supplied Radio Checklist

Table 1

Obtain the manual from the manufacturer of the radio.
Verify that the radio communicates Compact Measurement Records (CMR)s over RS232. Verify that the settings can be changed in order to match the Display.
Review the power requirements for the radio. Review any special requirements. The power for the machine may run to 28 VDC.
Validate the settings that are used to communicate with the base radio.	Radio channel
	Over-the-air data rate
Find pinout information for the Customer Supplied Radio.
Find the drawing or the pinout for correct machine.
Create a simple schematic from the information that was collected. The drawing should show which pins on the radio and the machine connector correspond to each other.
Create the harness. Use the simple schematic.
Install the harness on machine. Verify the power to the radio when the system is turned on.
Verify that AccuGrade System is receiving CMRs from the base station.

Troubleshooting

No Power To Radio

• Verify the connections to the power and the ground pins.

• Verify the input power that is required for the radio.

• If a converter has been added, ensure that the +PWR and Ground pins from the AccuGrade connector are connected to converter. Ensure that the +PWR and Ground pins from the converter are connected to the radio.

No Communication Through Radio

• Verify that the radio is a Data Terminal Equipment (DTE) device.

• If the radio is a Data Communications Equipment (DCE) device, modify the TX and the RX connections as shown in Illustration 2.

Illustration 2	g01260134

Note: It is critical to follow the documentation from the manufacture of the radio. This will ensure that the handshake and/or other communications start-up procedure is properly executed. A Customer Supplied Radio may require additional pins to be grounded or to be tied to voltage. These items will also be identified in the documentation from the manufacturer.