Except as otherwise provided in section 9340(c) (relating to when set-off ineffective) and unless the bank otherwise agrees in a signed record, a bank's rights and duties with respect to a deposit account maintained with the bank are not terminated, suspended or modified by:
(1) the creation, attachment or perfection of a security interest in the deposit account;
(2) the bank's knowledge of the security interest; or
(3) the bank's receipt of instructions from the secured party.