354 d

354D is not essentially based on vulgar messages or anything but pertains to a concept called Stalking.
Legally, it means repeatedly persuading a person to foster personal interaction despite clear indication of disinterest in the same from such person. 
Hence, even if you did not send any vulgar messages, the police can book you under such provision for what you meant to do was to initiate or maintain interaction. Now given the details of your case, being previously related as a husband and wife can either play in your favour or can similarly go against you as well. 

I suggest you consider this with your legal counsel who got you a bail in some other case, as you say, for proper legal advise and aid.

Considering the facts presented by you to be correct, I would suggest you to argue your case with full force before the Magistrate at the time of framing charges against you. You may argue that there was no persuation as such, your ex-wife didnt gave you clear indications that she was not interested as no reply to your Text can't be considered as no interest at her behest etc.

Consult with good counsel. 

Yours Sincerely,

Advocate NITIN KAPOOR

Mob: 8800692624