| gclib 307 Communications API for Galil controllers and PLCs |

All Data Structures Files Functions Variables Typedefs Macros Pages
gcaps.md
1 # gcaps {#gcaps}
2
3 ## FAQ
4
5 ### What is gcaps?
6 gcaps is a communication server natively supported by gclib to multiplex Galil hardware communication features. It runs in the background on the host computer, as a service or daemon.
7
8 Incidentally, the name *gcaps* is an acronym for the improbable name *Galil Controller Asynchronous Proxy Server*. Yet another tidbit to impress friends at parties.
9
10 ### How/When is gcaps used?
11 gclib will attempt to use gcaps whenever GOpen() is called without the `--direct` or `-d` switch. Other than this small difference, gclib function calls through gcaps or directly to the hardware behave identically. The first version of gclib supporting gcaps is 299.
12
13 ### Why should gcaps be used rather than direct connections?
14 Galil recommends gcaps for software development for a number of reasons. The following are a few of the best.
15
16 * Connections through gcaps multiplex a single connection resource. This means that single-channel connection protocols like RS232 or PCI can be shared with as many simultaneous connections as needed. Furthermore, Ethernet-based connections with gcaps leave plenty of Ethernet handles available for other communications, such as MODBUS.
17 * All communications features are available to all connecting clients. This means that a software application can be running simultaneosly with Galil's diagnostic software (Galil Design Kit). This significantly simplifies support and aides in debugging
18 * Data Records, Messages, and Interrupts everywhere. No longer does one connection *steal* data streams from another.
19
20 ### How do I install gcaps?
21 gcaps is bundled in the gclib and GDK installer packages. Install with defaults to get the gcaps service included. gcaps is also available as a standalone installer. Downloads are available on the <a href="http://www.galil.com/sw/pub/all/rn/gcaps.html">release notes</a> page.
22
23
24
25