IOCs

Wiki > The Backend System > Creating and Basics of IOCs

Before Creating an IOC

Remember, EPICS is a collaboration! Why create an IOC when you can just use one that's already out there? If the device is not ISIS specific, before thinking about creating an IOC check whether it is listed here and, if not, email the mailing list here.

Creating an IOC

Building a new IOC? Before you get started, take a look at the relevant instrument page to see if there's any useful information for the device you're about to write an IOC for. Otherwise, let's get going. If you have problems see See IOC and device Troubleshooting.

There are two sorts of IOCs, EPICs and pycaspy. For EPICs type see the automatic creation below for pycaspy see the pycaspy ioc.

Automatically

If you're building a new StreamDevice IOC you can use the IOC Generator script, for developer info see the wiki.

Manually

If you're not creating a StreamDevice IOC or you you would like to know how an IOC could be created manually see:

• Creating an ISIS StreamDevice IOC
• Creating an LvDCOM IOC
• Creating a simple IOC - usual basic way to make an IOC on new EPICS installation, not the way we do it in ISIS.

Fleshing out the IOC

1. You can now flesh out your IOC to work. I would encourage you to do this in a TDD style (if not write the tests afterwards) and make sure you follow the conventions. To write in a TDD style use:

   • IOC Testing framework
   • Emulating devices

   If you used the script to create your IOC an empty emulator and IOC tests will have been created for you.

2. Record simulation

3. IOC Finishing Touches

   • Additional for motors:
     1. Adding motor IOC to global motor moving and stop all
     2. Add support for motor extras, e.g. axes

4. Running (and testing) IOC

5. Add logging

6. Add any manuals used to the manuals directory

7. Add a page about the device in the correct categories in Specific Device IOC

8. Add IOC to EPICS hardware support list

9. Create an OPI and send it to instrument scientists for approval.

Conventions

• IOC naming

• ISIS PV guide

• PV naming

• PV units & standards

• Macro naming

• IOC Startup

Other

• aSub records
• Motor IOCs
• Libraries to include
• Creating a MODBUS IOC (page removed at some point)
• Using LVDCOM
• Convert Record
• Stream Device Tips and Tricks
• IOC Utilities includes general templates
• Removing or Renaming an IOC module
• IOC Testing framework
• Complexity of LabVIEW Drivers
• Typical start up log for an ioc
• Some Design thoughts for a serial/Ethernet IOC
• Reducing build dependencies for older iocs
• Template Substitutions
• Creating a State Machine
• Limited range on PV

Debugging IOCs

Debug builds of IOCs are built in jenkins and can be deployed to instruments, see here.

Specific IOC Information

For information on specific IOCs see Specific Device IOC

Further reading

• EPICS record reference manual
• IOC doxygen Documentation
• IOC message logging