Is the box welded shut with the electronics inside?
Is the electronics potted in solid silicone or epoxyee?

If not it seems to me then that the cost to outfit each box with an IRDA port and lens system is greater than that to simply open the cover and plug in a cable for an operation that is done seldom such as a re-programming operation.

On the other hand if either of the above is answered yes AND if IRDA is an intrinsic part or each unit in normal operation then go ahead and use it for re-programming. However if IRDA is not a part of the normal product operation I would then find a different way to do re-programming OR eliminate the need for re-programming by nailing down the code good enough that you could use a mask programmed part.

Michael Karas