德信PIML900/1800手册和开发板原理图，包括AT命令集。内部资料。-Tak Sun PIML900/1800 manuals and development board schematic diagram, including the AT command set. Internal information.

Cellon CMS91 GPRS终端拨号上网连接认证注册全过程研究 和PIML 900/1800 GPRS 使用说明与详细流程介绍-The whole process of research Cellon CMS91 GPRS dial-up Internet connection terminal certification registration And PIML 900/1800 GPRS Descr iption d