devSoftAsyn - Information and Download
EPICS Soft Asynchonous Device Support
This page is the home of the EPICS devSoftAsyn module, which provides soft asynchronous device support for standard EPICS output records.
This site gives access to the software source code, information on other modules which are needed to install and run it, and documentation on the how to include and use it in your EPICS applications. Please email any comments and bug reports to the module owner who is responsible for coordinating development and releases.
Where to Find it
You can download the software directly from the links in the table below:
Site Installation and BuildingAfter obtaining a copy of the distribution, it must be installed and built for use at your site. These steps only need to be performed once for the site (unless versions of the module running under different releases of EPICS and/or the other required modules are needed).
Documentation / Description
Often the EPICS programmer is confronted with the following problem: There is an output record with an asynchronous device support. But the data to be output must be preprocessed by one or more soft records before sending it to the hardware. Then, a normal ca or db put to one of the soft records will process synchronously i.e. will complete before the data is actually written to the hardware.
There are cases where this is not the desired behavior. Instead the front-end soft records should complete processing only after the asynchronous hardware record has completed. In order to achieve this, you can now use this asynchronous soft support to connect your soft record's OUT link to the hardware record's VAL. The connection will then act like an asynchronous link.
The technique to achieve this is the EPICS putNotify feature. Instead of performing a dbPutLink() on the OUT link, like the standard soft support does, the asynchronous soft support performs a dbPutNotify().
Like standard EPICS soft support, there are two flavors of soft asynchronous support: without conversion ("Asyn Soft Channel") and with conversion ("Asyn Raw Soft Channel"). Supported record types are:
The link type is INST_IO. The link definition syntax is:
The first parameter <pv-name> must be the name of a pv on the same IOC. The optional second parameter <timeout> must be a (floating point) number specifying the dbPutNotify timeout in seconds.
There is an optional configuration routine that may be called from the startup file:
Last modified: Wed May 7 16:47:57 2003
Maintained by: Benjamin Franksen <email@example.com>