VALVE-BALL 8T0080 - Caterpillar

The EMCP 4 has the following connections for communication:
Primary CANdata link (CAN 1)
Accessory CAN data link (CAN 2) (EMCP 4.4 only)
Modbus RTU (RS-485 Half duplex)-SCADA Data Link (EMCP 4.4 only)
RS-485 SCADA Data Link (Modbus RTU, Half Duplex) (EMCP 4.4 only)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 automatic voltage regulators (AVR) using the CAN protocol when the AVR supports CAN protocol
Provides communication with on-package expansion thermocouple modules for use with engine temperatures
Provides communication with the Caterpillar Clean Emissions Module SystemThe Cat Digital Voltage Regulator (Cat DVR) is an example of an AVR that is supported by the CAN protocol.Primary CAN Communication Wires
The primary CAN communication wires are brought out of the EMCP 4 as part of the 120 pin connector. The pin designations for the EMCP 4 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 EMCP 4.3 and EMCP 4.4.
Illustration 1 g02283818
EMCP 4.3 and EMCP 4.4 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 generator 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