Here's some more info from [Link: homeautomationnet.com]
The IR543 and IR543AH has a predetermined set of IR codes, just like your TV or VCR, so the remote will need to learn the IR543's or IR543AH's codes. There are a number of inexpensive remotes which come pre-programmed with the IR543's codes which makes programming your learning remote as easy as programming the remote to control any other device. The IR543AH's codes, however, are not available on off-the-shelf universal remotes so you'll need a computer programmable remote such as the Phillips Pronto. See the IR543AH section for more specific information.
How do I program my remote?
This depends on which transceiver you use and is addressed in detail in each transceiver's section.
The IR543 is supported by many off the shelf remotes and configuration files are available for download for the computer programmable remotes.
The IR543AH is NOT supported by any off the shelf remotes so you must have a computer programmable remote, or at least access to such a remote, which can then be used to teach your learning remote.
The IR543 and IR543AH require specific IR codes. Many universal remotes come pre-programmed with the IR543 codes but that isn't the case for the IR543AH. The HAN-01 and Ocelot learn any IR codes so compatibility is not an issue.