62(AinB1). They are also shown at the schematic on page 12 of datasheet (Rev A).
These two pins AinA1 and AinB2 are "Not Connected" on the Pin Configuration
What are these two pins used for?
AINA2 and AINB2 are for testing the Channel-to-Channel isolation.
The Channel-to-Channel isolation is tested with A Channel/50 Ω terminated
(AINA2) grounded and a full-scale signal applied to B Channel (AINB2).