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Introduction
The purpose of this Special Instruction is to provide a foundation for understanding, troubleshooting, and repairing various Ethernet layers. This document applies to Ethernet on all Caterpillar Equipment, Power Systems, and Aftermarket/Retrofit Systems. Technicians with various levels of skill should use this document as a single point of reference to provide guidance from start to finish. Other pieces of documentation may be available that are specific to certain Equipment, Power Systems, and Aftermarket/Retrofit Systems. Those documents should be used to reference specific software/hardware/system application knowledge.
The scope of this document will include 2 wire Ethernet and 4 wire Ethernet. The Ethernet technologies listed here may be serviced by Caterpillar Electronic Technician (Cat ET) for flashing, troubleshooting, ECM downloads, and configurations. Ethernet may also be used for Technology Enhancements such as retrofit upgrades, cameras, semi-autonomy, autonomy, and off board solutions.
This document will not describe how to perform all ET service over Ethernet. The Ethernet physical layer may be serviceable (replacement patch cable) and not serviceable (harness replacement). The document shall be outlined by the following sections:
- "Identifying Ethernet Problem (Symptom/Diagnostic)"
- "Cable Inspection"
- "Identifying Required Replacement Cables"
- "Ethernet Patch Cable Replacement"
Safety Section
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Personal injury or death can result from improper assembly procedures. Do not attempt any assembly until you have read and understand the assembly instructions. |
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Improper operation of an access platform could result in injury or death. Operators must carry out their duties properly and follow all instructions and guidelines given for the machine and access platform. |
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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manual. Failure to follow the instructions or heed the warnings could result in injury or death. Contact any Caterpillar dealer for replacement manuals. Proper care is your responsibility. |
Do not perform any procedure in this Special Instruction until you have read this Special Instruction and you understand this information. Use only proper tools and observe all precautions that pertain to the use of those tools. Failure to follow these procedures can result in personal injury. The following procedures also should be observed.
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.
A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.
Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.
Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. Ensure that any tool, procedure, work method, or operating technique you use that is not recommended by Caterpillar is safe.
Ensure that the product will not be damaged or the product will not be made unsafe by the operation, lubrication, maintenance, or repair procedures used.
Ground the equipment. Improper grounding will result in electrical current paths that are uncontrolled and unreliable. Uncontrolled electrical circuit paths can result in damage to the equipment. Uncontrolled electrical circuit paths can also cause electrical activity that may degrade the electronics and communications. Ensure that all grounds are secure and free of corrosion.
Before starting this installation, in addition to the normal safety precautions taken whereas performing maintenance on heavy machinery, the following lockout/tagout procedure is recommended:
- Move the machine to a smooth, level location, and away from other working machines and personnel.
- Lower the implements to the ground.
- Stop the engine.
- Engage the parking brake for the machine.
- Place the disconnect switch in the OFF position.
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Illustration 1 g06276183 Lockout tags - Place a lockout tag on the disconnect switch.
Ethernet Overview
2 wire and 4 wire Ethernet are widely used technologies to transport small and large amounts of information between two devices. The large amount of information may vary but can include flashing, camera/sound, ECM downloads, troubleshooting, map files, and GPS information. 2 wire and 4 wire are different technologies and are not interchangeable. The standards for 2 wire and 4 wire are different however operate in similar ways. A 4 wire channel should not plug into a 2 wire channel and a 2 wire channel should not plug into a 4 wire channel. Additionally, the cabling is not interchangeable and should not be used as a replacement for CAN. However, the possibility exists for devices and systems to have a combination of 2 and 4 wire Ethernet with other data links (CAN, CDL, Wi-Fi, etc).
System Communication and Design
Ethernet on Caterpillar systems communicates by a point-to-point style network. Point-to-point networks utilize two devices on 1 Channel. This design is different from CAN networks where all devices are connected on the same bus. Multiple point-to-point systems can be integrated with a hub to create a star network. The center of the star would be the hub or switch. The hub may commonly be seen as a display or network manager.
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| Illustration 2 | g06349989 |
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Bus | |
Bus - All devices connected to the same wires (CAN, CDL, ATA).
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| Illustration 3 | g06349993 |
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Point-to-point | |
Point-to-point - Two devices or more connected together in succession.
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| Illustration 4 | g06350000 |
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Star | |
Star - A hub with connections to multiple devices. Able to combine hubs to expand the network.
Communication Mode
There are three types of communication modes: simplex, half duplex, and full duplex. The types are defined as follows:
- Simplex communication only sends information in 1 direction. (Like TV stations, the end user is not sending feedback to the sender.)
- Half duplex allows communication of information in both directions but only 1 direction at a time. (Like push to talk 2-way radios that are impossible to speak and listen at the same time.)
- Full duplex allows communications of information in both directions at the same time. (Like cell phones, both users can talk and listen at the same time.)
2 wire and 4 wire Ethernet are intended to operate under full duplex. 2 wire Ethernet will only operate under full duplex. 4 wire Ethernet will regularly configure to full duplex but may automatically configure to half duplex if issues occur and communication is still required.
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| Illustration 5 | g06350010 |
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2 wire, 1 set twisted pair | |
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| Illustration 6 | g06350009 |
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4 wire, 2 sets of twisted pairs | |
2 Wire Ethernet
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| Illustration 7 | g06350022 |
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Example 2 wire Ethernet | |
2 wire Ethernet is commonly used in the following locations:
- B CAM
- D6:Cx displays
- A6 ECMS (A6:Nx, A6:Mx), PLE
| NOTICE |
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2 wire Ethernet cabling should not be modified. This list includes but is not limited to using different type of connectors, splicing, soldering, length modification, contact replacement, and jacket removal. |
2 wire Ethernet is configured for 100BASE-T1 (100Mb/s. 100BASE-T1 uses full duplex over a single pair. The only 2 wire Ethernet cable that Caterpillar supports uses a combination of Blue/White (No Shield) with a Jacket and Blue Stripe (with sealing). This cabling uses 2 wires to support full duplex operations; 2 wires for Both Tx (Data Transmit) and Rx (Data Receive). There are no legacy versions of 2 wire Ethernet. 2 wire and 4 wire Ethernet cable is not allowed to substitute each other. Due to higher bit transfer rates than CAN, CDL and 4 wire Ethernet, 2 wire Ethernet uses a lighter gauge wire and is required to use different connectors to maintain Ethernet Signal Integrity. 2 wire Ethernet should be combined only with connectors that the cable was designed for. Connector replacement of the same kind is allowed with 2 wire Ethernet patch cables.
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| Illustration 8 | g06350362 |
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2 wire and 4 wire used at the same time | |
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| Illustration 9 | g06350383 |
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2 wire and 4 wire used at the same time | |
4 Wire Ethernet
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| Illustration 10 | g06350016 |
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4 wire Ethernet example | |
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| Illustration 11 | g06350021 |
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4 wire Ethernet example | |
4 wire Ethernet is commonly used in the following locations:
- Service computers (to service with the machine)
- A CAM Gen 1 and Gen 2
- D6:Cx displays
- A5 ECMs (A5:Nx, A5:Mx, etc.)
- A6:Nx
- • Commercial off the shelf components (Cisco, Motorola, etc.)
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| Illustration 12 | g06350011 |
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4 wire Ethernet with green/orange/white | |
4 wire Ethernet utilizes a combination of 10BASE-T (10Mb/s) and 100BASE-TX (100Mb/s). Caterpillar equipment may use various types of 4 wire Ethernet cabling. The most common 4 wire Ethernet cable uses a combination of Green/Orange/White (No Shield) with a Jacket and Blue Stripe (with sealing). This cabling uses 4 wires to support full duplex operations; 2 wires for Tx (Data Transmit), 2 wires for Rx (Data Receive). Legacy variations of Ethernet wiring may be found using other color schemes and/or may include a shield. Ethernet cable without a shield should not be a direct replacement for an Ethernet cable using a shield and viceversa. 2 wire and 4 wire Ethernet cable is not allowed to substitute each other. 4 wire Ethernet may use connectors such as Deutsch, BR-44/49, BR-81, AMP, M12, or Other, and does offer some options for repair. If 4 wire Ethernet modifications need to occur, refer to "Modifying a 4 Wire Ethernet Patch Cable" in this document. If repairs must be made, Caterpillar recommends using the same design and connectors as used on the schematic.
Network Layer
The devices on the Caterpillar Ethernet Network LAN (Local Area Network) are communicating over the IPV4. The LAN is typically communicating on the 165.26.78.xxx and 165.26.79.xxx range. The LAN is defined by Caterpillar. In some instances, WAN can be defined by the customer. In other instances, Caterpillar will define the WAN. The protocols may vary between TCP and UDP for camera, flashing, service, and machine controls. When the configured bandwidth of 2 wire and 4 wire Ethernet is configured to 10Mbps and/or 100Mbps, the actual utilization of bandwidth will vary between equipment, machines, configurations, and software. Ethernet has an advantage over CAN and CDL for data transfer. The 10Mbps and 100Mbps data transfer is beneficial for servicing machines and is required for new technologies such as retrofit upgrades, cameras, semi-autonomy, autonomy, and offboard solutions.
Identifying Ethernet Problem (Symptom/Diagnostic)
Depending on the equipment and software, Ethernet issues can be identified as symptomatic and diagnostic code based. These issues can stem from both hardware and software. Symptomatic issues do not have a diagnostic code associated. An example may be such as "Unable to locate an ECM in Browse Product Network Devices or Winflash". The section below will help to identify the issue and begin troubleshooting Ethernet.
Connect to Cat ET Using Ethernet
Cat ET uses Ethernet for various purposes. When servicing on ET, Ethernet will have a benefit for faster flashes, downloads, and configurations. Perform the following procedure to connect to ET and Winflash over Ethernet:
- Open Electronic Technician.
- In Electronic Technician, select "Utilities>Preferences>Modify".
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Illustration 13 g06352568 "Communications" tab under "Preferences" - Under "Communications" change the selected tool to "Ethernet Direct Connection". Refer to Illustration 13.
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Illustration 14 g06352571 Adapter setting - Change the Ethernet adapter setting that corresponds with the PC, in this instance "Intel® Ethernet Connection (3) I218-LM". Refer to Illustration 14.
- Click "OK" to accept the changes.
- From this point, the user can select "Winflash", "Browse Product Network Devices", or "Connect".
Unable to Connect to Locate Any Devices in WinFlash or Browse Product Network Devices
An issue may occur that the Service PC will not be able to connect to a machine or locate any devices. Troubleshooting is embedded in Electronic Technician to help resolve issues with the Service PC through one of the following locations:
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| Illustration 15 | g06352944 |
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"Help>Troubleshooting" | |
- "Help>Troubleshooting"
- When the dialog box opens, open "Ethernet Direct Connection"
In this instance, perform the following procedure to help verify the connection between the Service PC and the machine:
- Using 305-5528 Wiring Harness or 385-8492 Cable As and 457-6114 Cable As, ensure that one end is plugged securely into the Ethernet Service Port on the machine and that the RJ45 connector-end is plugged securely into the network adapter slot on the PC.
- Verify that the status lights on the PC Ethernet port are illuminated. Generally, there are two lights, one light is continuously illuminated and the other light flashes according to network activity. On some ports, there may be only a single light that flashes with network activity.
- If no status light is illuminated, there is a physical wiring problem between the ECM and the PC. If no status light is illuminated, ensure the following actions:
- Verify that the device that is connected to the service port is powered. (Example may be a Network Manager or Display. Refer to the machine schematic.
- Verify continuity of the cable and/or substitute a different cable.
- Verify that the length of Ethernet cable does not exceed
3.05 m (10 ft) . - Confirm that the connections are clean and free of debris, grease, or fluids.
- Ensure that the port on the Service PC is not disabled by a system administrator. (Plug the Service PC into another device.)
- If a status light is red, consult the documentation for the network adapter. Under normal conditions, the lights are typically green, amber, orange, or yellow.
- If a status light is green, amber, orange, or yellow and flashing, perform the following procedure:
- Change the Ethernet Adapter Setting that corresponds with the PC. Refer to "Connect to Cat ET Using Ethernet" and try to reconnect.
- Ensure that the computer VPN is disabled or turned off.
- Navigate to "Ethernet Direct Connection Troubleshooting" in "ET>Help>Troubleshooting".
- If no status light is illuminated, there is a physical wiring problem between the ECM and the PC. If no status light is illuminated, ensure the following actions:
Unable to Locate an ECM in WinFlash or Browse Product Network Devices
An issue may occur that the Service PC will be able to connect to some devices over Ethernet but other ECMs may be missing. In this instance, either the software does not allow for Ethernet flashing or an issue has occurred that is preventing communication with that ECM. For troubleshooting one or more missing ECMs in WinFlash or Browse Product Network Devices, perform the following procedure:
- Understand the network topology. Locate the network topology by the one of the following methods:
- As a download in Electronic Technician
- In the troubleshooting guide
- From the schematic
Note: Ensure the importance in understanding how the ECMs are connected and designed. Refer to Illustration 16 for the details of how each device is connected and communicating.
- Identify the missing devices on the network topology. When the devices are identified, the possibility exists of locating the specific channel (between ECMs) that appears to be problematic.
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Illustration 17 g06352579 "Port Monitoring Status" - Check the port status. Refer to Illustration 17. The status of the Ethernet port can be monitored. The status of the port is in real time and displays icons to indicate the status. This information is communicated over CAN so when Ethernet is down, troubleshooting can still be performed. In ET, the status can be checked under "Diagnostic>System Communications>Port Monitoring". Press the "Plus" symbol to expand the chart and gather more information.
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| Illustration 16 | g06352578 |
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Network topology | |
The following details apply:
Port - Refers to the physical port of the device.
Status - Refers to the state of the port on the device: up, down, data, error or not supported. The status is being read from the Receive Side (Rx).
Transition Count - Refers to the number of changes a port has detected an Up-Down transition since device power-on. A change of up-down is 1 count. A change of up-down-up is 1 count. A change of up-down-up-down is 2 counts.
The following icons apply:
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- Not Supported or Unavailable |
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- The Ethernet Port is Up and transition count has not changed in the past 10 seconds. Showing "Up" indicates that the port is connected to another device. |
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- Transition Count is incrementing between up and down in the last 10 seconds. The transition count increases on the count of "Down". |
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- Transition Count is 0 and the Link is Down. |
The follow "Status" details apply:
Up - Indicates that this port is connected to another device. Device A is able to receive communication from Device B.
Down - Indicates that this port is not connected to another device. This device is not receiving any communication from Device B.
Data Error - The data being read is invalid or corrupt.
Not Supported - The status is not supported in the software.
Unavailable - The device is unable to read the status.
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| Illustration 18 | g06352948 |
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Example | |
Refer to Illustration 18 as the picture details multiple ports "Up" and 2 Ports with "!". The connection between the primary display and machine control appears to be a point of failure. Refer to the network topology and schematic to identify routing and design.
In this scenario, Port 5 of the Primary Display and Port 1 of the Machine Control should be used as reference. The specific wires should be references on the schematic to correctly pinpoint the issue.
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| Illustration 19 | g06352952 |
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"Port Statistics" | |
Detailed information of the port may be found under the following menu "Diagnostic>System Communications>Port Statistics". Click the "Plus" symbol for additional information on each port. Refer to Illustration 19.
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| Illustration 20 | g06352953 |
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Detailed information from ECMs | |
Under each ECM, "Port Statistics" will show detailed information from ECMs with Ethernet Ports. Each Port is defined by the pinout on the ECM. Refer to Illustration 20.
After confirming the specific channel that is problematic, refer to "Cable Inspection" for identifying concerns with the Ethernet wiring.
Cable Inspection
2 wire and 4 wire Ethernet is more sensitive to disturbances than J1939 CAN or CDL. Certain restrictions and precautions must be accounted for with Ethernet cables. These datalinks rely on electrical impedance as well as characteristic impedance. Variation in electrical impedance, characteristic impedance, insertion loss, and return loss (reflection) will have a negative impact on data integrity. These variations are a result of quality from an Ethernet Cable. Cable quality issues can come from assembly, installation, lifecycle, abuse, etc. The failure types outlined in this section call out issues that should be identified during the cable inspection. While these issues may not affect performance in other Datalinks (CAN, CDL, etc.), the issues may have exaggerated consequences under high-speed data transmission. A damaged cable may change the dielectric, capacitance and velocity propagation, resulting in an increase to insertion loss or decrease in return loss. Return loss is the loss of power in the signal, reflected (returned) on a single copper plane (for example reflection on a contact). Return loss is typically expressed in dB. Insertion loss is the loss of power in a signal when insertion of outside force occurs (for example voltage resistance, reflections, length of cable, or crosstalk). Mismatches may occur due to changes in electrical resistance. The Ethernet cables should be closely inspected, a visual inspection is frequently the best way to identify failures and issues.
Failure Types
While these inspection points are being highlighted for Ethernet, many of these points are a point in normal inspection for wiring and harnesses. A visual inspection is frequently the best way to identify failures and issues regardless of how the problem presents itself. The failure types have been noted with a performance impact rating. These performance impact ratings should help try to identify the highest chance in error with cabling. A Performance impact rating of "Severe" will use the most margin of error while a Performance impact rating of "Low" will use the lowest margin of error. Each machine will have a varying amount of margin of error and is a result of system design.
Smashing/Pinching of Cabling
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| Illustration 21 | g06350394 |
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Smashing/pinching of cabling | |
Performance Impact: Severe
Smashed or damaged cabling affects the resistance of copper and characteristic impedance of the wiring. Fluid entry may occur and cause change in corrosion and resistance. Cable or harness replacement is required to correct the problem.
Untwisted/Unjacketed Wiring
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| Illustration 22 | g06350395 |
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2 wire Ethernet | |
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| Illustration 23 | g06350397 |
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4 wire Ethernet | |
Performance Impact: Moderate
Untwisted wiring causes problems over time as the wiring can move and create wire separation. Twisting of wires provides immunity to electrical interference. Unjacketed wiring by itself is not always a problem. Untwisted wiring in combination with other factors like poor routing, moving cables or electrical noise can become a large problem. Cable or harness replacement may be required to correct the problem.
| Wire Type | Untwist Between Connector and Heatshrink |
| 2 Wire Ethernet | 5–7 mm |
| 4 Wire Ethernet | 45 mm Max |
Refer to Table 1 for allowable untwist/unjacketed area.
Wire Separation
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| Illustration 24 | g06350400 |
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Separation of wiring | |
Performance Impact: Significant
Separating of wires increases characteristic impedance and makes the cable less immune to electrical interference. Refer to Illustration 24. While this 4 wire Ethernet cable pictured does pass the specification for untwist/unjacketed area, the cabling is bad practice to allow separation of the wiring. The wire should be corrected by twisting the wires closer to the connector or adjusting the harness so separation does not occur.
Uneven Wire Lengths
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| Illustration 25 | g06350407 |
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Uneven wire lengths | |
Performance Impact: Severe
When wire lengths are different, separation of wiring occurs at the connector outside of the jacketing. Additionally, from the device, signals are sent at the same time and intended to arrive at the same time. The differences in length cause minor time delays between the pair. Patch cable or harness replacement may be required to correct the problem. However, the possibility may exist that a contact is not fully seated. To perform an inspection, perform a pull test and check for loose contacts. If the contact is fully seated and a "hook" is still present, remove the Ethernet cable and check the total end length. The total end length is the difference between length of wire and contacts in a twisted pair.
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| Illustration 26 | g06350410 |
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Wire end length | |
| Wire Type | Wire End Length Difference |
| 2 Wire Ethernet | 1 mm Max |
| 4 Wire Ethernet | 2 mm Max |
Refer to Table 2 for total end length with contact installed.
Damaged Jacket/Insulation
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| Illustration 27 | g06350418 |
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Damaged jacket/insulation | |
Performance Impact: Moderate
Damaged jacketing and insulation are an issue for many reasons: allows for entry of fluids, indicates that the cable has been damaged, corrosion of copper/contacts, and possible grounding to other circuits. There may not be an immediate impact of damaged jacket or insulation but over time this impact will create a problem. Patch cable or harness replacement is required to correct the problem.
Fluid Entry in Jacketing
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| Illustration 28 | g06350698 |
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Fluid entry in jacketing | |
Performance Impact: Severe
When an Ethernet cable is damaged or not installed properly, the possibility for water, oil, or other fluids to enter behind the jacket. The fluid will displace the air and possibly change the insulation properties (making the insulation soft or malleable). The fluid may be more conductive or less conductive, creating issues with differential pairing of Ethernet signals. Patch cable or harness replacement is required to correct the problem.
Kink or Sharp Bend Radius
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| Illustration 29 | g06350703 |
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Kink or sharp bend radius in cabling | |
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| Illustration 30 | g06350707 |
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Kink or sharp bend radius in cabling | |
Performance Impact: Low
A sharp bend can kink the elongate the copper and stress the insulation/jacketing. The changes in the cable are permanent, regardless of how the cable is rerouted. The elongation and stressing will make the Ethernet signal less immune and have a negative effect on the signal. Patch cable or harness replacement is required to correct the problem.
Incorrect Bundling of Cable
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| Illustration 31 | g06350710 |
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Incorrect coiling of cable | |
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| Illustration 32 | g06350908 |
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Incorrect bundling of cable | |
Performance Impact: Moderate
Ethernet cabling should not be bundled in a loop when in use and transmitting data. Bundling wiring in a loop creates an inductance ring and will create noise and disturb signals. Additionally, bundling wiring like this looping may create cross talk within the cable. Increased noise will decrease the signal to noise ratio. Bundling the patch cable into the correct position will correct the problem.
Too Many Interconnects
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| Illustration 33 | g06350715 |
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Too many interconnects | |
Performance Impact: Moderate
All Ethernet systems are built to meet specific design requirements. Every interconnect will slightly degrade the Ethernet signal. Caterpillar recommends not to add additional interconnects. Adding interconnects may make a functioning system more susceptible to failures and less immune. When using patch cables, keep the interconnects near original system design. Patch cable or harness replacement is required to correct the problem.
Incorrect Pinout (Cable Separation)
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| Illustration 34 | g06350734 |
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Schematic pinout | |
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| Illustration 35 | g06350735 |
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Incorrect pinout | |
Performance Impact: Significant
Refer to Illustration 34 and Illustration 35as the pictures detail how Ethernet should not be wired. Separating of wires increases characteristic impedance and makes the cable less immune to electromagnet interference or crosstalk. This issue will significantly reduce the signal to noise ratio. The schematic will detail the best pinout for Ethernet. The connector should be repinned to correct the issue.
Excessive Long Cabling
Performance Impact: Low
Patch cables with excessive unused length should not be selected for machine use. Only patch cables called out on the electrical schematic or service magazine should be used. These cables have been preselected to best fit the circuit and limit the unused length. Patch replacement is required to correct the problem.
Splicing of Cabling
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| Illustration 36 | g06350726 |
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Splicing | |
Performance Impact: Severe
Soldering, splicing, or reconnecting damaged Ethernet cables is not allowed. These modifications to the Ethernet cables severely impact signal integrity. Patch cable or harness replacement is required to correct the problem.
Cable Placed Next to Noise Source
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| Illustration 37 | g06350740 |
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View of Ethernet cable strapped to alternator | |
Performance Impact: Moderate
Ethernet patch cables should not be routed near or around electrical noise sources such as solenoid drivers, injectors, electrical motor, high voltage, high current, etc. Only use the original existing harness and existing route for Ethernet patch cables. Ethernet cables and connectors should be routed
Contact Corrosion
Performance Impact: Significant
Corrosion may occur on copper and contacts that have been exposed to the elements or mistreated. Ethernet cable with any corrosion will distort Ethernet signals and differential pairs. Patch cable or harness replacement is required to correct the problem.
Dielectric Grease or Contaminated Contacts
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| Illustration 38 | g06350741 |
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Contaminated contact | |
Performance Impact: Significant
| NOTICE |
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Dielectric grease may be used to prevent corrosion however, Caterpillar strictly forbids with use on datalinks (especially Ethernet). |
Dielectric grease and other fluids change the dielectric constant and increases return loss. Isopropyl alcohol shall be used as a cleaning agent but Patch cable or harness replacement may be required to correct the problem, depending on severity.
Identifying Required Replacement Cables
Perform the following procedure to outline where to locate correct Ethernet patch cable replacement part numbers specific to a machine:
- Using SIS, locate the correct electrical schematic for the machine.
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Illustration 39 g06350751 (1) Ethernet patch cable table - Load the "Main Schematic" and locate the "Ethernet Patch Cable" table (1).
- After locating the "Ethernet Patch Cable" table on the schematic, the following descriptions apply to the table (1):
"Part Number" - Refers to the part number of the replacement Ethernet patch cable.
"ID" - Refers to the harness ID which the circuit ID and replacement Ethernet patch cable applies to.
"Circuit Number" - Refers to the range of circuit numbers that correspond to the replacement Ethernet patch cable.
"Description" - Refers to the selection of 2 wire or 4 wire Ethernet with the length (in meters).
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Illustration 40 g06350764 Ethernet patch cable reference table Note: Illustration 40 is a reference from Service Magazine, M0088075 and may be updated.
- If an Ethernet patch cable table does not exist on the schematic, a service magazine may be available with this information:
"Part Number" - Refers to the part number of the replacement Ethernet patch cable.
"Description" - Refers to the selection of 2 wire or 4 wire Ethernet with the length (in meters).
"Location" - Refers to the location of the harness and patch cable routing on the machine.
"ID" - Refers to the harness ID which the circuit ID and replacement Ethernet patch cable applies to.
"Circuit" - Refers to the range of circuit numbers that correspond to the replacement Ethernet patch cable.
"Harness" - Refers to the part number of the harness that corresponds to the circuit ID and replacement Ethernet patch cable.
Note: These Ethernet patch cables do not come assembled with connectors. Connectors should be ordered separately.
Ethernet Patch Cable Replacement
While the requirements for Ethernet are similar across the board, this guidance will be done using both 2 wire and 4 wire BR Series Ethernet cables. Installing an Ethernet patch cable may be done for various reasons:
- Troubleshooting
- Short-term repairs
- Long-term repairs
- Failed Ethernet cable inside a machine harness
- Failed Ethernet cable outside of a machine harness
- New installations of attachments
- System upgrades
| NOTICE |
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Due to the high-speed nature of Ethernet and machine/user dependency on Ethernet, extreme caution should be taken when installing an Ethernet patch cable and performing Ethernet repairs. |
The information below will outline considerations that can improve longevity of the Ethernet system and prevent machine downtime if used. This information includes errors and mistakes that should not be overlooked. Ethernet integrity issues will not affect all data and applications the same. Ethernet integrity issues affecting applications such as loading webpages, downloading information, and flashing may not be greatly noticed by users. Other applications such as video, sound, machine controls, and performance information may have a great negative impact when problems are introduced.
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| Illustration 41 | g06350813 |
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2 wire bend diameter equal 66mm | |
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| Illustration 42 | g06350815 |
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4 wire bend diameter equal 88mm | |
Note: Violating the bend radius requirement will result in signal loss and will be disruptive to communication between ECMs. Ensure that a 2 wire bend diameter is equal to
Note: The 100 Mbps data rate of the Ethernet signal has low tolerance for sharp bend radius.
Note: If the cable tie is excessively tight, the Ethernet Cable may kink and cause signal degradation.
| NOTICE |
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Do not modify the Ethernet patch cable. The cable has been built and certified electronically to function correctly within the specified performance band for this Ethernet application. |
Guidelines
Ensure that the following guidelines are adhered to for installation:
- Do not create a new routing for the patch cable. The replacement patch cable should only follow the existing harness and existing route for Ethernet.
- Do not use excessively long cable. Only use patch cables noted that on the schematic for the circuit intended.
- Do not modify the Ethernet cable length. Extra cable length should be bundled by using a figure-8.
- Do not use smaller than recommended cable ties, only use 7K-1181 Cable Strap. Using other, smaller cable ties can deform the cable with pinch points and introduce issues into the system.
- Do not install contact pigtails on Ethernet. If a contact has failed or is suspect, patch cable or harness replacement is required.
- Do not modify the contacts. (The only modification allowed is installation of a Deutsch on a 4 wire Ethernet patch cable.)
- Do not kink the Ethernet cable at the connector or in the cable. Kinks and sharp bends can be removed by properly routing and installing the Ethernet patch cables. Kinks may be introduced by overtightening the cable ties.
- Do not add in excessive amounts of connectors. Using correct sized patch cables will keep interconnects to a minimum.
- Do not introduce poor bundling. Correctly bundle the additional harness length into a figure-8. The additional length should be properly strapped in a neat and clean fashion.
- Do not coil the cable as coiling will add significant noise to the system and degrade the signal. Extra length should be bundled in a figure-8 pattern.
- Do not install connectors in vertical positions as water entry may occur. Connectors should be installed horizontally to allow water run off.
- Do not place Ethernet patch cables near or around electrical noise sources (solenoid driver, injectors, electrical motor, high voltage, high current, etc.) Only use the original existing harness and existing route for Ethernet patch cables. Ethernet cables and connectors should be routed
300 mm (11.81 inch) away from noise sources.
Installation Procedure
| Required Parts | |
|---|---|
| Quantity | Part |
| - | 2 Wire Ethernet patch cable or 4 Wire Ethernet patch cable |
| - | 7K-1181 Cable Strap |
| 1 | 326-8203 Tool |
| |
| Illustration 43 | g06350801 |
|
Ethernet patch cable | |
| |
| Illustration 44 | g06350802 |
|
Example of a 2 wire Ethernet patch cable | |
| |
| Illustration 45 | g06350810 |
|
Example of a 4 wire Ethernet patch cable | |
Perform the following procedure for the correct installation and bundling processes for an Ethernet patch cable:
- The correct length of replacement Ethernet patch cable must be selected. Check for the length value on the label on the failed Ethernet cable. Select the shortest Ethernet patch cable available that will still span the same distance as the failed Ethernet cable.
Note: Always select the shortest possible length to minimize signal losses, especially on multi-segment channels that approach the 15 meter limit. The schematic will detail the correct patch cable that should be used to replace a segment.
- Cut the ends of the failed Ethernet cable. Removing the existing failed Ethernet cable from the machine is not necessary, especially if the cable is contained within a braided harness. The ends of the failed Ethernet Cable can be cut off close to where the cable exits the braid or tied back to prevent interference.
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Illustration 46 g06350879 Connecting cable - Connect the labeled end of the new Ethernet patch cable to the end that is easiest to access. Loosely route the entire patch cable, using 7K-1181 Cable Straps along the intended path to the opposite end and connect the cable. Route the new Ethernet patch cable along the same path as the failed Ethernet cable. Refer to Illustration 46.
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Illustration 47 g06350882 Figure-8 looping - Determine routing and plan where the excess Ethernet patch cable length will be bundled up. Also, the location of the figure-8 should also be placed so that the movement of the cable itself can be restricted. Refer to Illustration 47.
- Identify the Ethernet patch cable routing. The replacement patch cable should only follow the existing harness and existing route for Ethernet. Ensure to minimize the following areas:
- Rubbing/chafing of the sheath
- Interference from electrical noise sources. Ensure to keep a minimum distance of
300 mm (11.81 inch) away. - Damage due to moving parts (articulation joints, actuators, hoses, etc).
- Damage due to foreign contact areas, debris areas, water/snow accumulation, etc.
- Melting or degradation from nearby heat sources (exhaust manifolds, brakes, etc).
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Illustration 48 g06350874 Spacing cable straps - Tighten the 7K-1181 Cable Straps using the 326-8203 Tool, at the end furthest away from the chosen figure-8 loop section. Space the cable straps at 8-16 inch intervals. Refer to Illustration 48.
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Illustration 49 g06350869 Bundling
(1) Center
(2) Each end - If extra length is present, bundle the length into a figure-8 loop and loosely secure the loop using 3 Cable straps using the 326-8203 Tool. Secure one cable strap to center of figure-8 loop and the two remaining on each end of loop. Refer to Illustration 49.
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Illustration 50 g06350871 Measuring bend radius - Use a ruler to ensure that the correct bend radius requirement is being maintained. Refer to Illustration 50. In this example, the figure-8 has a bend radius greater than minimum specification and is acceptable to use.
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Illustration 51 g06350886 Adjusting the bend - Ensure to make the necessary adjustments to meet the bend requirement and then tighten the cable straps using the 326-8203 Tool. Refer to Illustration 51.
Modifying a 4 Wire Ethernet Patch Cable
Modification is allowed only on a 4 wire Ethernet patch cable. Some 4 wire Ethernet patch cables may need modified by removing a BR series contact and installing Deutsch contacts on 1 or both ends. Perform the following procedure to modify a 4 wire Ethernet patch cable:
- Identify the 4 wire Ethernet patch cable that needs to be modified. Refer to Illustration 52.
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Illustration 53 g06350898 Removing contacts - Cut off the contacts. Refer to Illustration 53.
Note: The end length of the twisted pair must be even. Cut both wires at once to ensure this length.
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Illustration 54 g06350899 Unshielding wires - Strip or unshield all wires evenly to accommodate Deutsch contact pin. Refer to Illustration 54.
- Crimp Deutsch contact onto wire.
Note: After crimping, retwist the wire.
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Illustration 55 g06350900 Inspecting wires - Perform an inspection on the total end length of the wires. Both wires should be within 1mm of each other. Refer to Illustration 55.
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Illustration 56 g06350903 Inserting contacts into connector - While maintaining full twist to the connector, push contacts into connector. Refer to Illustration 56.
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Illustration 57 g06350904 Measuring untwisted/unjacketed area - Perform an inspection on the untwisted/unjacketed area of the Ethernet cable. The untwisted/unjacketed area should not exceed
45 mm (1.77 inch) .
| |
| Illustration 52 | g06350897 |
|
4 wire Ethernet patch cable to modify | |
Reference Section
Tx - Data transmit
Rx - Data receive
LAN - Local Area Network
WAN - Wide Area Network
Capacitance - This term is the ability for an object to store electrical energy. Some objects are designed to store electrical energy other objects have the natural ability to store energy.
Insertion Loss (Attenuation) - Insertion loss is the loss of power in a signal when insertion of outside force occurs (for example voltage resistance, reflections, length of cable, or crosstalk).
Return Loss - This term is the loss of power in the signal, reflected (returned) on a single copper plane (for example reflection on a contact). The loss is typically expressed in dB.
Velocity of Propagation - This term is the speed of a signal through the full length of the cable.
Dielectric - This term is a substance that transmits electric force without conduction, an insulator.
EMI (Electromagnetic Interference) - This term is an external force that generates an electromagnet field that interferes and degrades with datalink communications. These external forces can be ignition systems, high voltage/high amperage