sim300c是希姆通公司的GSM/GPRS模块，将该模块和MCU连接，可以通过模块提供的AT来控制模块，收发短信，并且可以登录到GPRS网络，连接到Internet上。该文档就是sim300c的AT指令集，及其作用和参数解说等。-sim300c is Simcom' s GSM/GPRS module, the module and MCU connections provided by AT module to control module, send and receive text messages, and can log on to the GPRS network, connected to the Internet. This document is sim300c the AT command set, and the role and parameters of interpretation and so on.