Communications Hub Function [CHF]

Means either a SMETS1 CHF; or that part of a device installed (or to be
installed) at a premises, which:
(a) consists of the components or other apparatus identified in; and
(b) as a minimum, has the functional capability specified by and complies
with the other requirements of,
a Version of the CHTS (but excluding those provisions that are described as
applying only to ‘Gas Proxy Functions’) which was within its Installation
Validity Period on the date on which the device was installed.