(i) the signal shall not assume an ‘off’ aspect unless the line is
clear not only upto the next Stop signal in advance but also for
an adequate distance beyond it, and
(ii) the signal is automatically placed to ‘ON’ as soon as it is passed
by...
more... the train.
(2) Unless otherwise directed by approved special instructions, the
adequate distance referred to in sub-clause (i) of clause (c) of
sub-rule (1) shall not be less than 120 metres.
9.02 Duties of Loco Pilot and Guard when an Automatic Stop signal
on double line is to be passed at ‘ON’:-
(1) When a Loco Pilot finds an Automatic Stop signal with an ‘A’
marker at ‘on’, he shall bring his train to a stop in the rear of
the signal. After bringing his train to a stop in the rear of the
signal, the Loco Pilot shall wait there for one minute by day
and two minutes by night. If after waiting for this period, the
signal continues to remain at ‘ON’, he shall give the prescribed
code of whistle and exchange signals with the Guard and then
proceed ahead, as far as the line is clear, towards the next Stop
..
apparently ''A" Sign represents green(Allowed to go with speed restriction and following certain guidelines) so it wouldn't be right to say that train enters in section even thought when it receives a Red signal in ABS.