This source code in Delphi 7.0. Have function to decoding and encoding PDU format to ASCII and from ASCII to PDU. You can modify it or change it for meet your requirement.

前几天要做一个短信收发的小软件 使用标准AT指令 现在只能支持PDU模式（Text模式太简陋）！ 支持7_Bit 和 UCS2 编码 集成了串口（spcomm） 只需要简单的配置几个参数就可以收发短信了-A few days ago to do a little messaging software Using standard AT commands Now only support PDU mode (Text mode is too simple!