LINES GP-WATER 1261337 - Caterpillar

Customer Supplied Radio
The AccuGrade System for GPS must use a radio that is compatible with the local GPS base station radio. Caterpillar currently offers the CR900 and TC450C for the AccuGrade System. These radios require Trimble infrastructure radios for compatibility. For sites that are using non-Trimble infrastructure, customer supplied radios may be connected to the AccuGrade System. However, the customer supplied radio will need to be configured for use with the AccuGrade System. This document outlines the wiring issues that must be addressed in order to provide communication with the AccuGrade System. Caterpillar makes no claim to compatibility with all radios. Additionally, Caterpillar assumes no responsibility for the performance of the system integrating customer supplied radios.The following recommendations must be considered when installing a customer supplied radio:
18-gauge wire is recommended for all lines. Avoid narrower gauge wire.
Machine pinouts may vary, refer to the Electrical Schematic for each machine to determine correct pinouts.
These instructions do not address any unique power requirements that may apply to individual customer supplied radios.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.
Locate the schematic for the connector for your customer supplied radio.Refer to the owner's manual or the documentation from the manufacturer.
Verify that 24 VDC nominal power is acceptable.Note: If there are any limitations on input power, find a suitable converter, this should be wired between the AccuGrade connection and the connection for the customer supplied radio.
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
Locate the Electrical Schematic for the AccuGrade System and the specific Caterpillar machine. Schematics are available on SISWeb.
Find the 8-pin connector for the GPS radio.
Trace back from the 8-pin connector to the 12-pin Deutsch connector.Note the pin number for the following connections:
+ PWR
GRND
COM 2 TX
COM 2 RX
Wire the new cable.Use the pinouts that are noted in Steps 1 and 2.
Illustration 78 g01259989
Customer Supplied Radio Example
Field Conditions
Existing AccuGrade compatible GPS base station
Customer supplied radio at the GPS base stationRequired
Create a cable that connects a compatible customer supplied radio to the AccuGrade System.
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 AccuGrade System.
Will the machine radio operate within 9-32 VDC.Note: Verify all necessary connections can operate at machine voltages.Answer - By looking in the radio documentation found that radio can run on 9-32 VDC, but in order for radio to function the DTR line needs to be tied high and it has a limitation of 25 VDC.Solution