GASKET 4D3145 - Caterpillar

The OCP has the following connections for communication:
Primary CAN data link (CAN 1)
Accessory CAN data link (CAN 2)
Modbus RTU (RS-485 Half duplex) - SCADA data link
RS-485 SCADA data link (Modbus RTU, half duplex)Primary CAN Data Link (CAN 1)
The data link module is equipped with a communications connection that utilizes CAN 1. The connection provides the following features:
Set point configuration
Allows core software and language text files to be "flashed"
Password protection for different levels of authorization
Same password strategy applies to the entire control
Provides communication with the engine control module (ECM) using the CAN protocol
Provides communication with on-package expansion thermocouple modules for use with engine temperatures
Provides communication with the Caterpillar Clean Emissions Module SystemPrimary CAN Communication Wires
The primary CAN communication wires are brought out of the OCP as part of the 120 pin connector. The pin designations for the OCP connector are shown in Table 1.
Table 1
Primary CAN Communication Wires
Pin # Name Description
43 CAN 1- Differential (-) for CAN
30 CAN 1 SH Shield for CAN
32 CAN 1+ Differential (+) for CAN The primary CAN data link uses bus type construction that consists of a main trunk and drops off the trunk. The features that apply to the bus system are as follows:
The maximum allowable trunk length is 40 m (131 ft)
Maximum drop length is 1 m (3 ft)
Requires a 120 ohm termination resistor at the ends of the main trunkRefer to Illustration 1 as an example of the CAN bus wiring for the OCP.
Illustration 1 g02951380
OCP CAN 1 wiring diagram example
Accessory CAN Data Link (CAN 2)
The CAN 2 accessory data link connection proves the following features:
Use with local and remote communication
Annunciator can be installed up to 244 m (800 ft) from the control module
Supports a maximum of four CAN annunciators modules
Supports only Caterpillar approved modules
Provides connection for use with the digital expansion input/output modules
connection is provided for use with the thermocouple and RTD modules
The total number of optional modules not to exceed four annunciators, four I/O modules, and two temperature modulesTable 2 lists the supported modules for the CAN 1 and CAN 2 data links.
Table 2
MODULE OCP
Primary CAN Accessory CAN
Electronic Engine Controller 2 0
CAN Annunciator 0 4
Thermocouple 1 1
RTD 0 1
DIO 0 4 Accessory CAN Data Link (CAN 2) Wiring
The accessory CAN communication wires are brought out of the OCP as part of the 120 pin connector. The pin designations for the OCP connector are shown in Table 3.
Table 3
Accessory CAN Communication Wires
Pin # Name Description
42 CAN 2- Differential (-) for CAN
41 CAN2 SH Shield for CAN
31 CAN2+ Differential (+) for CAN The accessory CAN data link uses bus type construction that consists of a main trunk and drops off the trunk. The features that apply to the bus system are as follows:
The maximum allowable trunk length is 244 m (800 ft)
Maximum drop length is 3 m (9 ft)
Requires a 120 ohm termination resistor at the ends of the main trunkRefer to Illustration 2 as an example of