I'm currently using an IR-543 to control my X10 Appliance module. This module is controlling a bias light.

I would like to disable programming on my ApplianceLinc Applicance module. According to the manual, I should send:
M16 O16 P16 N16 M16

My IR-543 only has buttons for channels 1-8, and no lettered buttons. Can anyone explain what I'm missing here? How do I send the above?

I have an MX-850 and the supplied software has X-10 codes. Some codes are all numbers, others are all letters. Could someone shed some light on this?

To clarify, the reason I want to disable programming on the module in the first place - Every week or so my applicance Module stops successfully switching on/off the light. The light on the module flashes as though it's getting a signal, but no actual switching occurs. Any idea why this would be?