aSub records

Introduction

aSub records are useful when the output of a device is too complicated to be reasonably parsed in .protocol files.

DB records

Build files

Declare a .dbd file with the names of all the functions declared in the C file which will be called by EPICS.

function(function_name)
function(another_function_name)
[...]

In the make file references need to be added for the .dbd file and the C code:

LIBRARY_IOC = APPNAME
DBD += appname.dbd

APPNAME_DBD += asyn.dbd
APPNAME_DBD += asubFunctions.dbd

APPNAME_SRCS += c_sources.c

APPNAME_LIBS += $(EPICS_BASE_IOC_LIBS)
APPNAME_LIBS += asyn utilities
APPNAME_LIBS += asubFunctions

Where APPNAME is to be replaced with the name of the new support module being built.

In the support/{...}/configure/RELEASE file reference all libraries which will be required to compile the new support module.

For example, a minimum set required will be:

ASYN=$(SUPPORT)/asyn/master
ONCRPC=$(SUPPORT)/oncrpc/master
SNCSEQ=$(SUPPORT)/seq/master
UTILITIES=$(SUPPORT)/utilities/master
ASUBFUNCTIONS=$(SUPPORT)/asubFunctions/master

The IOC makefile will now need to be updated with the files that have just been produced

$(APPNAME)_DBD += LIBRARY_NAME.dbd

$(APPNAME)_LIBS += LIBRARY_NAME

Here, $(APPNAME) is a macro, and LIBRARY_NAME will need to be replaced with the name of the support module that was just created.

C code

Need to define a C function which will be called by the aSub record:

static long function_name(aSubRecord *prec)
{
    return 0;
}

Need to tie in this function to the epics database with a call to epicsRegisterFunction:

epicsRegisterFunction(function_name);

Escaping to C++

C++ code