Trunk sequence seems not working

Hi Everyone,

I am using Digium FXO card TDM400P for my zap trunking. It has 3 port for FXO and it is working fine. What I seems to have a problem is that a trunk sequence it seems not working. The two FXO ports are connected onto 2 different PSTN provider respectively. I make an outbound on trixbox and 2nd PSTN is set as secondary trunk sequence, just incase pstn1 is busy or the terminal is taken off from the FXO port.

Is there a solution on this one? Maybe on conf but I do not know what conf's should I configure.

Thanks in advance...