Creating an IOC Application

Tags: user developer

This example shows how to create an IOC Application with an IOC using StreamDevice to talk to devices, e.g., via ethernet.

Create a directory for the IOC Applications. For example $HOME/EPICS/IOCs

mkdir IOCs
cd IOCs

Create a top for an IOC called sampleIOC

mkdir sampleIOC; cd sampleIOC -t example sampleIOC -i -t example sampleIOC
Using target architecture darwin-x86 (only one available)
The following applications are available:
What application should the IOC(s) boot?
The default uses the IOC's name, even if not listed above.
Application name? (just return)

Now, by running make, a sample IOC like the demo/test IOC is built. Next, we want to add asyn and StreamDevice to the IOC. For this, we add the stream and asyn libraries to the Makefile. Edit sampleIOCApp/src/Makefile and add the block

#add asyn and streamDevice to this IOC production libs
sampleIOC_LIBS += stream
sampleIOC_LIBS += asyn

The application must also load asyn.dbd and stream.dbd to use StreamDevice. This can be put into a generated dbd, e.g into xxxSupport.dbd which already gets included by the Makefile. So the xxxSupport.dbd now reads:

cat sampleIOCApp/src/xxxSupport.dbd
include "xxxRecord.dbd"
include "stream.dbd"
include "asyn.dbd"

To find the dbd files, you have to add the paths to these files in configure/RELEASE:

# Build variables that are NOT used in paths should be set in
# the CONFIG_SITE file.
# Variables and paths to dependent modules:
# If using the sequencer, point SNCSEQ at its top directory:
#SNCSEQ = $(MODULES)/seq-ver

If make was done before, make distclean is probably required. Anyway, then make. The newly created IOC can be run with:

cd iocBoot/iocsampleIOC/
chmod u+x st.cmd

Not very interesting yet, because there is no database file nor a protocol file.

ls -la sampleIOCApp/Db/
total 56
drwxr-xr-x 11 maradona  staff   374  Jun  1  16:47  .
drwxr-xr-x  5 maradona  staff   170  Jun  1  12:46  ..
-rw-r--r--  1 maradona  staff   523  Jun  1  12:46  Makefile
drwxr-xr-x  2 maradona  staff    68  Jun  1  16:47  O.Common
drwxr-xr-x  3 maradona  staff   102  Jun  1  16:47  O.darwin-x86
-rw-r--r--  1 maradona  staff  1761  Jun  1  12:46  circle.db
-rw-r--r--  1 maradona  staff  1274  Jun  1  12:46  dbExample1.db
-rw-r--r--  1 maradona  staff   921  Jun  1  12:46  dbExample2.db
-rw-r--r--  1 maradona  staff   286  Jun  1  12:46  dbSubExample.db
-rw-r--r--  1 maradona  staff   170  Jun  1  12:46  sampleIOCVersion.db
-rw-r--r--  1 maradona  staff   307  Jun  1  12:46  user.substitutions

Note that this is a Db directory and not the db directory that is in ./sampleIOC. For MDOxxxx scopes by Tektronix, the database (.db) and protocol (.proto) file can look something like

cat MDO.db
record(stringin, $(P)$(R)idn){
    field(DESC, "Asks for info blabla")
    field(DTYP, "stream")
    field(INP, "@MDO.proto getStr(*IDN,99) $(PORT) $(A)")
    field(PINI, "YES")

cat MDO.proto
Terminator = LF;
    out "$1?";
    in "%s";
    @replytimeout {out "$1?"; in "%s";}

Now, we add to sampleIOCApp/Db/Makefile the information that these files must be included in the compilation. So

cat sampleIOCApp/Db/Makefile
include $(TOP)/configure/CONFIG
# Install databases, templates & substitutions like this
DB += circle.db
DB += dbExample1.db
DB += dbExample2.db
DB += sampleIOCVersion.db
DB += dbSubExample.db
DB += user.substitutions
DB += MDO.db
DB += MDO.proto
# If .db template is not named *.template add
include $(TOP)/configure/RULES

Again, make in directory sampleIOC. Finally, we add IP port configuration, setting the Stream path and loading the database to the st.cmd file. The st.cmd should read:

cat st.cmd


#- You may have to change sampleIOC to something else
#- everywhere it appears in this file

< envPaths

epicsEnvSet ("STREAM_PROTOCOL_PATH","$(TOP)/db")

cd "${TOP}"

## Register all support components
dbLoadDatabase "dbd/sampleIOC.dbd"
sampleIOC_registerRecordDeviceDriver pdbbase

## Load record instances
dbLoadTemplate "db/user.substitutions"
dbLoadRecords "db/sampleIOCVersion.db", "user=UUUUUU"
dbLoadRecords "db/dbSubExample.db", "user=UUUUUU"

#IF if the user also defines EPICS_CAS_INTF_ADDR_LIST then beacon address
#list automatic configuration is constrained to the network interfaces specified
#therein, and therefore only the broadcast addresses of the specified LAN interfaces,
#and the destination addresses of all specified point-to-point links, will be automatically configured.
#epicsEnvSet ("EPICS_CAS_INTF_ADDR_LIST","")

# connect to the device ... IP-Address ! Port 2025 used by textronix, see manual

## Load record instances
dbLoadRecords("db/MDO.db", "P=UUUUUU:,PORT=L0,R=MDO:,L=0,A=0")

#- Set this to see messages from mySub
#var mySubDebug 1

#- Run this to trace the stages of iocInit

cd "${TOP}/iocBoot/${IOC}"

## Start any sequence programs
#seq sncExample, "user=UUUUUU"

In here, you have to replace UUUUUU with the user name that runs the EPICS IOC (you?). bbb.bbb.bbb.bbb is the IP of the device (e.g. the scope) and pppp the port on which it listens. EPICS_CAS_INTF_ADDR_LIST can be used if there are two network interfaces (e.g. wlan and eth0).

The following commands might be necessary with multiple network interfaces:

export EPICS_CA_ADDR_LIST=ccc.ccc.ccc.ccc << Broadcast address of the network