NX also provides the MOM postprocessor that can properly format tool paths for specific types of machine/controller combinations. The MOM postprocessor, like GPM, also requires several elements:
the Event Generator - is the core module that will cycle through the events in the part file.
the Event Handler - is a file containing a set of instructions dictating how each event type is to be processed.
the Definition File - is a file containing static information related a particular machine tool/controller combination.
the Output File - is the file where the postprocessor puts the postprocessed NC instructions that will be read and executed by the machine tool.
The Event Generator, the Event Handler, and the Definition File are dependent upon each other. Together they transform the tool path data contained in the part file into a set of formatted instructions that they can be read and executed by a specific machine tool/controller combination.
The MOM postrocessor:
Uses the Event Generator to read the events (tool path data) in the part file.
Each event is processed according to the instructions contained in the Event Handler.
The resulting instructions are format according to the information contained in the Definition File.
The postprocessed machine control instructions are written to the Output File.
Figure 1-5 The tool path data is postprocessed according to the instructions in the Event Generator and the formats in the Definition File.
The following section describes the processing steps required to postprocess a tool path. An illustration summarizes these steps.
This section describes the several requirements for postprocessing using the MOM postprocessor. To simplify the description of the process, the requirements are presented as sequential steps in the following order:
Create an Event Handler
Create a Definition File
Create the tool path in NX
Create a Postprocessed File
Prior to postprocessing tool path data, you must create an Event Handler (with the extension .tcl) for the type of machine/controller you plan to use to cut the part. The Event Handler contains a detailed set of instructions for processing each event type.
Prior to postprocessing tool path data, you must also create a Definition File (with the extension .def) for the type of machine/controller you plan to use to cut the part. The Definition File contains instructions about:
General machine attributes.
The addresses that are supported for the particular machine.
The attributes of each address (format, minimum value, maximum value, etc.)
A set of block templates that describe how the addresses fit together to perform the desired action at the machine tool.
Create the desired tool paths using the Manufacturing application. For detailed information on the use of this application , refer to the NX Manufacturing Online Help.
As described previously, the MOM postprocessor is a program that reads the tool path data and converts it, according to the instructions in the Event Handler and the formats in the Definition File, into machine-readable commands that are compatible with the particular machine/controller combination that you will use to cut the part.
You can postprocess with the GPM by invoking the POSTPROCESS option in the Operation Manager.
You are require to select the name of the machine tool that you are postprocessing for from the list box and specify the name of the Output File (with the extension .ptp) in the text field.
Finally, you can load the tool path information into the machine tool controller and machine the part.
Refer to Figure 1-4 for an illustrative summary of these steps in postprocessing.
Figure 1-6 The above illustrates the stages of MOM Postprocessing a tool path in order to operate a particular machine.