Spectra error codes on an HHCH

[kcbooboo]

Since the HHCH only has two seven-segment characters, how, if at all, do the various ER and FL codes get displayed on that unit?

Does it try to simulate those characters, then flash the device code, then the error code, using hex characters 0-9, A-F?

What happens with a FAIL 001 or a FAIL 999 code?

I've searched several basic service manuals and they only talk about the A2/A5/A7 and A9 formats, where there are 8 or 11 characters on the VFD. No mention of code displays on the HHCH.

Thanks.

Bob M.