The PL1000E Communication Electronic Control Module (ECM) requires a “Parameter Configuration List” (PCL) file in order to execute parameter translations. The PCL file contains the definition of parameters on the source data link. The source data link can be either CDL or J1939, or both CDL and J1939. The PCL file contains the definition of how the parameters are to be translated onto the destination data link. The destination data link can be either Modbus “remote terminal unit” (RTU) or Modbus TCP. There are several processes and work products that are involved in the creation of a successful parameter translation configuration.
Each process will be discussed in the following sections.
Parameter Translation Files and Configuration Tools
Prior to a discussion of the procedure required to configure the PL1000E Communication ECM parameter translation, it is necessary to discuss a few work products used throughout the process.
Parameter Translation Editor (PTE)
The PTE provides a user interface through which a user may design and architect the communications paths within his system. It is a software application available as a utility application within Cat ET and the Caterpillar Communications Toolkit.
Parameter Translation Editor File (*.pte)
The PTE file contains a list of all parameters for a set of engine models that are available for translation. A PTE file is specific to parameters available on either CDL or J1939. Parameters that are listed within the PTE file may be selected and may be assigned a Modbus register through Cat ET or Caterpillar Communications Toolkit.
Note: The registers are not pre-assigned registers in the PTE file.
Parameter Configuration List (PCL) File (*.pcl)
The PCL file is the output of the PTE application. After a user has designed the desired ECM objects and associated translations in the PTE and chooses to save the file, a *.pcl file will be created. This file then contains all of the information about the parameter necessary for translation to Modbus.
Create Parameter Translation Design
- In the Cat ET application (version 2007B or later) or the Caterpillar Communications Toolkit (version 2007B or later), select the Parameter Translation Editor (PTE) from the “Utilities” menu.
Note: Connection to the PL1000E is not necessary in order to use the PTE. The PTE software provides an interface for manual translation design. The PTE software also provides a PCL wizard for more rapid translation design for simpler systems. Each of the translation design methods are covered in the sections that follow. However, due to the importance of the interface, the interface will be discussed first. An explanation will be provided for the terms and objects that are used in the following sections.
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| Illustration 1 | g01708133 |
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(1) Properties Window (2) Default PTE Directory (3) Ellipse Toggle Button (4) Save As Button (5) Design Window |
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Familiarization with the Parameter Translation Design Interface
File Operations
The “New” button clears the design interface and prepares the PTE for creation of a new Modbus Slave or Modbus Master file.
The “Open” button initiates a standard windows “Open” dialog that can be used to load a previously created *.pcl into the design window.
The “Save” button causes the PTE to commit the information within the design window to a *.pcl file.
The “Save As” button (4) initiates a standard Windows “Save As” dialog. The “Save As” dialog can be used in order to save the information within the design window to a new *.pcl file. The”Save As” function is useful when using a previously created *.pcl file as a starting point on a new project. The previously created file can be opened in PTE and then can be saved as a new file name. Parameters can be added or removed in order to create the *.pcl file for the new project. Refer to the Systems Operation Troubleshooting Testing and Adjusting, RENR8091, “Parameter Translation Configuration” section of this document for details concerning the execution of this process.
Properties Window
When a device within the design window (large white area in the middle of the screen) (5) is selected, the “Properties” window will list the information that is related to that type of object. If no objects exist within the design window (5) or if the user has clicked on the white part of the design window, then the properties window will display the information related to the overall design. Refer to Illustration 1. The following sections present information about the objects and the associated properties that can be displayed.
Object – Design Window
- Demand Time Out – Total amount of time in milliseconds that on demand parameters remain enabled when no additional read requests are made from the Modbus Master. Since on demand parameters are not implemented in the current design of the PL1000E, the “Demand Time Out” value has no significant impact on the resulting parameter translation design.
- Default PTE Directory – The “Default PTE Directory” is the directory on the computer where the *.pte files are located. Keep all *.pte files in one central location. In order to set the *.pte value, click on the button that is located to the right of the “Default PTE Directory”. An Open dialog will appear. Use the Open dialog in order to locate the appropriate folder. Refer to Illustration 1.
Object – CDL ECM
A “CDL ECM Object” in the design window represents a Caterpillar control attached to Cat DataLink. One of these types of objects must be added to the design for each Caterpillar control from which data is to be collected. For instance, some Caterpillar engine models have an engine controller, combustion module, and temperature sensing module. If data is desired from all three of these devices, then a separate “CDL ECM Object” must be added to the design window for each device. Refer to Illustration 2 for example of the properties window for a CDL object.
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| Illustration 2 | g01336076 |
- Type – “ECM Object Type” that is selected in the design window. The valid types are CDL, J1939, Webserver, and Modbus. The “Type” field is read only.
- PTE File Path – Displays the path and filename of the *.pte file assigned to the selected ECM object. This field is read only.
- ECM ID – A unique number that is assigned to the selected “ECM Object”. Each “ECM Object” in the design window must be assigned a unique ECM ID. When a *.pcl file is generated, this number will allow the on board software to differentiate between each “ECM Object” that is in the *.pcl file.
- Description – Free form text field that may be modified in order to give a visual indication of what the “ECM Object” represents within the system that is being designed. For instance, if the “CDL ECM Object” selected will represent the engine controller in the application, this text field can be modified to indicate that the object is the “36XX Engine Cntrl”. The maximum length of characters is equal to 20.
- Address – The data link address of the ECM Object. Electronic controls attached to CDL and J1939 data links must use an address to communicate on the associated data link. Refer to the documentation for the specific electronic control device in order to determine what value must be entered in the address field. Most engine controllers default to using the address “36” on CDL but this may vary depending on the application. Refer to the “Data Link Address of Caterpillar Electronic Control” section of this document.
Object – J1939 ECM
A “J1939 ECM Object” that is in the design window represents a Caterpillar control that is attached to the J1939 Data Link. One of these type of objects must be added to the design for each Caterpillar control from which data is desired to be collected. For instance, some Caterpillar engine models have an engine controller, combustion module, and temperature sensing module. If data is desired from all three of these devices, then a separate J1939 Object must be added to the design window for each device. Refer to Illustration 3 for an example of the properties window for a J1939 object.
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| Illustration 3 | g01336078 |
- Type – ECM Object Type of the object selected in the design window. The valid types are CDL, J1939, Webserver, and Modbus. This field is read only.
- PTE File Path – Displays the path and filename of the *.pte file assigned to the selected ECM Object. This field is read only.
- ECM ID – A unique number assigned to the selected ECM Object. Each ECM Object in the design window must be assigned a unique ECM ID. When a *.pcl file is generated, this number will allow the on board software to differentiate between each ECM Object in the *.pcl file.
- Description – Free form text field that may be modified in order to give a visual indication of what the “ECM Object” represents within the system that is being designed. For instance, if the “CDL ECM Object” selected will represent the engine controller in the application, this text field can be modified to indicate that the object is the “36XX Engine Cntrl”.
- Address – The data link address of the ECM Object. Electronic controls attached to CDL and J1939 Data Links must use an address to communicate on the associated data link. See the documentation for the specific electronic control device in order to determine what value must be entered in the address field.
Object – Modbus ECM
A Modbus ECM in the design window represents a Modbus interface to the PL1000E Communication ECM. The characteristics and attributes that are assigned to this object represent the definition of the Modbus Slave Device. The Modbus Slave Device will communicate with the Modbus Master Device. Multiple Modbus ECM Objects may be included in the design window, but each must be assigned to a different physical port of the ECM. Multiple Modbus ECM Objects may not be added to the design window and assigned the same Port attribute, or the *.pcl file will be unusable by the on board ECM software. Refer to Illustration 4 for an example of the properties window for the Modbus ECM object.
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| Illustration 4 | g01336084 |
- Type – ECM Object Type of the object selected in the design window. The valid objects types are CDL, J1939, webserver, and Modbus. This field is “read only”.
- ECM ID – A unique number assigned to the selected ECM Object. Each ECM Object in the design window must be assigned a unique ECM ID. When a *.pcl file is generated, this number will allow the on board software to differentiate between each ECM Object in the *.pcl file.
- Description – Free form text field that may be modified in order to give a visual indication of what the “ECM Object” represents within the system that is being designed. For instance, if the “Modbus ECM Object” that is selected will represent the “ECM Modbus TCP Slave” in the application, this text field can be modified to indicate that the object is the “PL1000E TCP”.
- Modbus Slave Address – The Modbus Slave Address to which all Modbus commands should be addressed to retrieve data as defined in the parameter translation arrows. This Modbus slave address is not the same address configured through Cat ET or Websever.
- Port – The physical port of the ECM on which the selected Modbus Slave Device should be accessible. If multiple ports are needed for each port, a modbus must be defined. Valid ports are RS-232-1, RS-232-2, RS-422, RS-485 (4 wire), RS-485 (2 wire), or TCP standard.
Object – Translation
A Translation Object appears on the design window as an arrow indicating the direction of data flow. The direction of data flow indirectly also shows the read/write accessibility of data. In other words, if there is a translation arrow pointing from the CDL ECM Object to the Modbus ECM Object, this indicates the Modbus Slave Device will only support register read commands for the parameters assigned to this translation object. Modbus register write commands will only be supported in J1939 to Modbus translations. An arrow pointing from the Modbus ECM Object to the CDL ECM Object indicates the Modbus Slave Device will only support register write commands for the parameters assigned to this translation object.
If it is desired to read and write a parameter, then that parameter must be assigned to translations in both directions.
Note: Defining a parameter for register write capability does not mean the CDL or J1939 ECM devices will support a write for these parameters. Closed loop control of write-able parameters is strictly the responsibility of the Modbus Master Device. The PL1000E Communication ECM is designed with the intention to provide remote system control. Caution should be exercised when attempting parameter writes J1939 to Modbus.
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| Illustration 5 | g01336128 |
- Parameter – The drop down menu contains a list of the parameters that are available for assignment to the selected Translation Object. When a parameter is selected from the drop down menu, the selected parameter is added to the parameter listing. Also, a new “click here to add” row will be added to the properties window.
- Request Rate – Time in milliseconds the PL1000E will wait before attempting to obtain updated data from the ECM Object from which this data is being translated. If this time elapses and the PL1000E is unable to obtain updated information from the source ECM Object, this data will be considered to be “stale”. The minimum valid value for this data is 500 milliseconds.
- Modbus Register – These registers are assigned in sequential order starting with 40,001 as the parameters are added. When the program assigns the Modbus Registers it calculates the appropriate amount of registers for each parameter. These registers may be reassigned automatically with a new starting address or manually changed.
Note: When manually changing registers, take caution that the registers do not interfere with other existing parameters which have already been assigned.
The Modbus Master may request a read of a parameter at a faster rate than that defined for the Request Rate, but the data associated with this Modbus Register will only be updated within the PL1000E at the assigned request rate.
Note: The request rate configuration should be considered carefully for each parameter. Smaller request rates will increase the amount of additional messaging on the source data link. Dynamic parameters such as Engine Speed or Load Factor can be obtained at a faster update rate, while less dynamic parameters such as Temperatures and Pressures can be obtained at a slower rate. Defining translations for a large number of parameters at the minimum request rate could cause excessive loading of the source data link and affect performance of the electronic controls attached to that data link.
Object – Web Server
A Web Server ECM in the design window represents a Web interface to the PL1000E Communication ECM.
Type – ECM Object Type of the object selected in the design window. The valid types are CDL, J1939, Modbus, and WebServer. This field is read only.
ECM ID – A unique number assigned to the selected “ECM Object”. Each “ECM Object” in the design window must be assigned a unique “ECM ID”. When a *.pcl file is generated, this number will allow the on board software to differentiate between each “ECM Object” in the *.pcl file.
Description – Free form text field that may be modified to give a visual indication of what the “ECM Object” represents within the system being designed.
Refer to Illustration 6 for an example of the properties window for the “WebServer” ECM object.
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| Illustration 6 | g01336142 |
Manual Parameter Configuration List Creation
Refer to Illustration 7 for creating a simple system parameter configuration list. Illustration 7 is an example of a system consisting of one engine controller, one PL1000E Communication ECM, and the Modbus Master Device. The Modbus Master Device is shown here only for reference. The configuration and operation of the Modbus Master Device is outside of the scope of this document.
For the example shown in Illustration 7, we have assembled a simple translation from Cat Data Link to Modbus RTU (using the RS-232 Port 1 of the PL1000E) for a Caterpillar 36XX model engine. The *.pte file used is a sample file and the Modbus Register assignments discussed are arbitrarily chosen for use in this example.
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| Illustration 7 | g01398013 |
The following information refers back to Illustration 7 as needed to give system perspective to some of the new terms and concepts used with the PL1000E Communication ECMs Configuration and the use of the PTE design interface.
Set the Default PTE Directory
Before starting the design process, ensure the Default PTE Directory represents the location of the desired *.pte files. For this example, all of the *.pte files have been located in the C:\PL1000E Example\ directory.
To set the default directory, perform the following steps.
- Identify the current default directory. Refer to Illustration 1.
- Copy PTE files from CD to chosen location on PC. (In this example, C:\PL1000E Example\directory is used).
- Click on the ellipse button. Refer to Illustration 1.
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| Illustration 9 | g01336160 |
Add a CDL ECM Object
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| Illustration 10 | g01336162 |
Click on the “Add ECM Object”. Refer to Illustration 10. Select “CDL” from the resulting drop down menu.
Note: PTE files are located on CD with PL1000E.