EPICS Previous

EPICSEPICS CA Proxy Gateway Module

Module Owner / Current Author:
Ralph Lange

This page is the home of the EPICS CA Proxy Gateway module, which is a proxy server for the Channel Access Protocol.

This site gives access to the software source code and documentation on how to include and use it in your EPICS environment. Please email any comments and bug reports to Ralph Lange who is the current author responsible for coordinating development and releases. Stephanie Allison and John Hammonds are also familiar with this module and may be willing to help with some problems.


The CA Proxy gateway is an application that uses a CA client on the lower interface to connect to channels (PVs) and sets up monitors to those channels. It uses the portable Channel Access Server (CAS) to provide these channels to other CA clients (the upper interface). The channels' data is cached. There is an EPICS Access Security layer within the Gateway to configure whose clients from which hosts may have read or write access to a channel provided by the Gateway.

Please refer to the Gateway talk (given at the Y2K spring EPICS Collaboration meeting) for an overview and general usage examples. Talks at later conferences are less detailed.

Hardware Supported

The module supports the following platforms / operating systems:

Where to Find it

You can download the software by HTTP from BESSY directly from the links in the table below:

Module Version Release Date uses EPICS Release Files
1.3.0 May 3rd, 2000 Patched 3.13.2 Base Patches
Gateway Sources
1.3.1 June 16th, 2000 Patched 3.13.2 Base Patches
Gateway Sources
1.3.2 Feb 11th, 2002 Same patched 3.13.2 Base Patches
Gateway Sources
1.3.3 Jul 19th, 2002 Same, but with an
additional patch (see release note)
Base Patches
Gateway Sources

Required Modules

Except the appropriate EPICS Base with the right set of patches, the Gateway requires the GNU regex library (version 0.12). You can either use a library that already has been installed at your site or download it from your favourite ftp server or from here.

Site Installation and Building

Here's a simple step-by-step recipe that should get you through installation:

1. Get a regular 3.13.2 base and unpack it in some directory (let's call it <baseGateway> here).
2. Go there, make it writable and unpack baseInsert-n.n.n.tar.gz, which contains all the needed patches in base.
3. Adjust <baseGateway>/config/CONFIG_SITE and build <baseGateway>. The make targets inc.host and buildInstall.host should do the job.
(Note: If you patch an existing base installation you might have to uninstall the gdd and CAS headers before compiling.)
4a. Go <somewhere>, unpack, configure and build the regex-0.12 library. Caveat: When compiled out-of-the-box, the regexp library is not optimized. Try setting CFLAGS=-O3 on the make command line to get a faster and smaller library.
4b. Find the object and include file of the regex library (comes with GNU Emacs).
5. Set up some (extension-style) <TOP> where you want to build the Gateway.
6. Go there and unpack extensionsInsert-n.n.n.tar.gz.
7. Build the Gateway. (Make sure your <TOP>/config/RELEASE points to the special <baseGateway> and the appropriate locations for the regex binary and header files.)


The CA Proxy Gateway documentation is still a bit sparse:

Release Notes

The Gateway still needs a specially patched version of base. Bringing it back to work with an off-the-shelf 3.14 base is on top of my personal Gateway to-do-list. Expect this to happen quite soon (rather months than years).

Changes for 1.3.3

Changes for 1.3.2

Changes for 1.3.1

Changes for 1.3.0

EPICS Previous Valid HTML 4.01!