“Which file does the machine need?” is often the first question on a machine control job, and the answer is rarely one word. Trimble and Topcon each have their own file types, and the right one also depends on the system and software version in the cab. This guide covers the files each platform typically works from and what to tell us, so the model is built for the machine you actually have.
If you are still pulling the drawings together, start with our checklist of what to send for a machine control model. This article picks up at section 5 of that list: the machine and its system.
Exchange files and machine files
Most jobs involve two kinds of file.
- Exchange files. LandXML and DXF or DWG come out of design software such as Civil 3D. They carry surfaces and linework in a form most systems can import, but not every machine reads them directly.
- Machine files. Each manufacturer has its own formats, usually produced in its office software or converted in its field software. They package the surfaces and linework the way the controller expects.
Alongside the design, the machine needs the site calibration, which Topcon calls a localisation. It ties the design coordinates to the positions measured on site. A correct model with a missing or mismatched calibration will not line up on the ground.
The lists below are the file types each manufacturer’s own documentation describes. Which files we deliver for your job is agreed at scope, before modelling starts.
Trimble machine control files
Trimble has more than one machine control system, and they do not all read the same files. On the machine, the main split is between GCS900 and Trimble Earthworks. Siteworks, Trimble’s rover software, has its own list.
- GCS900: the design surface as an SVD file and the linework as an SVL file, with the site calibration as a CFG file.
- Trimble Earthworks: LandXML, DSZ or VCL designs. A DSZ holds a single surface. A VCL or LandXML file can hold several surfaces, and a VCL can also carry filled linework. Surfaces must be full triangulated (TIN) surfaces, not stringline or cross-section definitions. The site calibration loads as a CAL file.
- Siteworks on the rover: TTM, VCL or LandXML surfaces, and DXF, DWG, VCL or LandXML linework. The calibration comes from a DC or JXL file.
What to tell us for Trimble
- The system: GCS900, Earthworks, or a Siteworks rover only, plus the firmware or software version shown on screen.
- For Earthworks, whether you want DSZ or VCL, if your hirer or dealer has a standard.
- The project name exactly as it shows on the controller, if the job is already loaded. If the name does not match, the screen can end up showing it as a second project.
- Whether the machine runs on GNSS or a total station (UTS), and the site control points as a CSV.
- The calibration file (CAL, CFG, DC or JXL) if one exists.
Topcon machine control files
Topcon’s Pocket-3D field software and 3D-MC machine software work with a project file, the TP3. One TP3 can hold several kinds of data, and each has its own file type when it travels on its own:
- TN3: triangulated (TIN) surfaces.
- LN3: linework, in 2D or 3D.
- RD3: alignments, such as a road centreline with its cross-section data.
- PT3: points.
- GC3: the site localisation and its localisation points.
Pocket-3D can import DXF and LandXML into a project. Whether a particular control box will take anything other than Topcon files depends on the system and its software version, so we confirm it for each job.
The GC3 matters. It carries the localisation points, so a localisation measured with the rover can be copied to the machines on the same job. If the site already has one, send it.
What to tell us for Topcon
- The control box or system name and its software version.
- Whether a project already exists on the machine or rover. If it does, send the TP3, or at least the GC3, so new surfaces line up with the existing localisation.
- Whether you want one TP3 or separate surface and linework files.
- Who does the localisation on site, and when.
Quick reference
| Platform and system | Files typically used | What to tell us |
|---|---|---|
| Trimble GCS900 | SVD surface, SVL linework, CFG calibration | System, firmware version, calibration file |
| Trimble Earthworks | LandXML, DSZ or VCL; CAL calibration | DSZ or VCL preference, project name on screen |
| Trimble Siteworks rover | TTM, VCL or LandXML surfaces; DXF, DWG, VCL or LandXML linework; DC or JXL calibration | Software version, calibration file |
| Topcon (Pocket-3D, 3D-MC) | TP3 project, or separate TN3, LN3, RD3, PT3 and GC3 files | Control box and version, existing TP3 or GC3 |
| Not sure | We confirm the file type with you before building | Machine type and a photo of the screen |
File types depend on the system and software version, and are confirmed for each job before modelling starts.
What to tell us for either platform
- The coordinate system, zone and height datum. For Melbourne jobs that is usually GDA2020 or GDA94 in MGA zone 55, with levels on AHD, plus the geoid model if one was used. For UK and New Zealand jobs, the local grid and datum.
- The site control, and any calibration or localisation file.
- Which surfaces you want as separate models: finished surface, subgrade or bulk earthworks level.
- Any export specification from your hirer, dealer or surveyor. Send it with the drawings.
- What the operator should see: the design names, which surface the cut and fill reads from, and which lines show on screen. For drainage and road-boxing linework, see what a GPS data package can show your site crew.
Not sure what is in the cab?
That is common, especially with hired machines. Send the machine type and a photo of the screen showing the system name and software version. We confirm the file type with you before building.
Ready to send a job? Use the quote form and attach the drawings with the machine details above, or read more about our machine control models.