These API examples are a collection of quick-start projects that demonstrate host computer communication with a Galil controller using the programming language of your choice. The output of a Microsoft Visual Basic API example is shown below.

Figure 1: Sample Microsoft Visual Basic API example program output.

Each API example project is contained in a .zip file and includes the following.

The gclib API is recommended for all new designs of supported controllers, and should be considered when updating existing projects.

API examples are available for the GalilTools Communication Library as well as prior generation libraries.

GalilTools Communication Library

Hierarchy of the GalilTools Communication Library

Figure 2 helps define the hierarchy of the GalilTools Communication Library. The following should be taken into consideration when choosing which level of the GalilTools Communication Library to use.

API Programming Examples for GalilTools Communication Library

Local and Host Programming

Commercial digital motion controllers are more flexible and more easy to use than analog or proprietary solutions because they can be programmed to perform a specific task. All modern Galil controllers can be used in two different ways as outlined below.

1. Local Programming: A Galil DMC program file is downloaded to the controller. This program is then run from the controller's local memory. Using local programming exclusively can eliminate the need for a computer altogether, thus eliminating cost and complexity.
2. Host Programming: Individual Galil DMC commands are sent from a host computer to the controller's communication bus (Ethernet, RS-232, USB, PCI, etc.). The host could be a computer running Windows, Linux, QNX or it could be an embedded device such as a touch screen. This method is often used when many devices (motion controller, barcode scanner, vision system, etc.) must be coordinated by a host.

A combination of methods 1 and 2 may also be used. This gives the option of offloading specific tasks to the motion controller, leaving high-level tasks to the host.

How to Use API programming Examples

The source code below is from the GalilTools Communication Library > GalilTools COM Library > Visual Basic 2010 project. This source file is found in the .zip file along with an instructive readme file.

Since each API example download includes a complete example, the projects can be compiled and run with minimal effort. If there are any issues, please make sure that the Galil library reference has been added to the project and that the library has been installed. Complete instructions are included in the readme.

What Next?

The API examples can be quickly adapted to meet the requirements of a real motion control application. The commands seen in the examples will be replaced with application-specific commands similar to those in Listing 1.

'Command String            Description
PRX= 1000;'                Move the X axis 1000 counts
BG X;'                     Begin motion
MG _BGY;'                  Y axis still in motion
MG _RPZ;'                  Z axis commanded position
MG @IN[1];'                State of digital input 1?
SB 1;'                     Set digital output 1
MG _LFW;'                  State of W axis forward limit switch
MG MyArray[3];'            Value of element 3 of MyArray
MG MyVar;'                 Value contained in the variable MyVar

Using a Galil library allows programmers to quickly generate motion, query whether motion is complete, set and get I/O point states, query axis positions, variables, array elements, and much more. See your controller's command reference and user manual for more information.

Some application specific examples can be found on the Galil C++/COM API Example Code page.

Please see the Event Driven Programming Tech Talk for more information about the data record and interrupts.

Avoid Trippoint Commands

Note that the following trippoint commands are not normally sent from host programs because they may require a long time to execute and block further communication until they complete.

AA, AD, AI, AM, AP, AR, AS, AT, AV, MC, MF, MR, WT

Similar functionality can be gained by looking at the data record, polling, or using interrupts. For example, MG _BGn (where n is the axis of interest) can be polled instead of using AM. Examples that monitor for motion completion can be found on the Galil C++/COM API Example Code page under the Motion Complete Example Code.

If you do decide to send any of these commands from a host and you are working with a controller that allows you to do so, be aware of the following.

Application Examples

Review the code below to see how easy it is to use the GalilTools API to create feature rich applications. Each "Example" project shows a small amount of code that demonstrates a specific function. Demo applications can be found on the Sample DMC Code page.
See a full listing of the example code descriptions in the examples manual.

Legacy Programming Libraries

The API legacy programming examples use older libraries and drivers that are incompatible with recent versions of Windows. Accordingly, they are not recommended for new applications. The GalilTools Communication Library is recommended for all new designs of supported controllers, and should be considered when updating existing projects.