SLEEVE 2255965 - Caterpillar

General Information
The resistance of a given material changes as the temperature of the material changes. A Resistive Temperature Device (RTD) uses the principle in order to measure temperature. An RTD is a passive device that requires an external excitation current. Once the current is supplied to the RTD, the voltage is read across the RTD terminals. The voltage is converted into a temperature using a simple mathematical algorithm.
Illustration 1 g02280216RTD Module Features
The RTD module contains the following features:
Capable of reading eight platinum RTD inputs
All 8 channels scanned in 2 seconds, 250 ms per channel
Inputs can have two, three, or four wire configurations
Calculate the temperature in degrees celsius
Broadcast temperature information onto the CAN data link
Capable of generating diagnostics
Overall drift with temperature is 15m ohm per degree Centigrade (maximum)
Maintains functionality with no loss in performance during single set point configuration
Maintains functionality with no loss in performance during communications on the data link
Will continue to operate normally if the communication data link is terminated
Retains all configured values in nonvolatile memory so that no information is lost when the module is de-energized
Configured on the accessory CAN data link using the Cat ET
Operates on the EMCP 4 Accessory CAN data links
Node address is automatically configuredNote: The four wire configuration is the most accurate. The four wire configuration uses one pair of wires for the excitation current and a separate pair of wires to measure the voltage.The EMCP 4 will read the information from the RTD module and display the information on the display screen.The diagnostics that are generated by the RTD module are maintained in non-volatile memory. The diagnostics are saved in order to ensure that the diagnostics are available following a power loss.Specifications
Table 1
RTD Specifications
Operating voltage range 5 VDC to 32 VDC
Nominal voltage 12 VDC or 24 VDC
Overvoltage capability 32 VDC for 1 hour at 85 °C (185 °F)
Ambient storage temperature −50 °C (−58 °F) to 125 °C (257 °F)
Ambient operating temperature range(1)(2) −40 °C (−40 °F) to 120 °C (248 °F)
Optical isolation(3) 500 VDC from input to ground
Burden less than 200 mA
Inrush not to exceed 800 mA
(1) If the ambient temperatures exceed 85 °C (185 °F), the RTD module may deviate in accuracy +/- 1°C.
(2) If the ambient temperature exceeds 120 °C (248 °F), the RTD module may not return to proper operation.
(3) Three-way isolation is provided for the CAN line, inputs, and power supply.Note: Power supply inputs are protected against transient surges and short circuits. Power supply inputs are isolated from I/O modules.RTD Wiring
Illustration 2 g02280294
Power and CAN bus connector wiring
Illustration 3 g02280295
Typical RTD sensor wiring
Illustration 4 g02280333
Typical RTD wiring connections
RTD Module Configuration
RTD modules can be programmed the use of Cat ET. Cat ET can also be used to flash program RTD modules in order to update software. Cat ET must be installed on a Windows based personal computer. The communication adapter must be connected between the PC and the CAN data link on which the target RTD module is connected.Note: Cat ET may be connected to the EMCP 4 accessory data link service connector.Use