GTM-201-RS232 is a new product designed by ICP DAS. It’s an industrial Quad-band GPRS/GSM modem with RS-232 interface that works at frequencies of GSM 850 MHz, EGSM 900 MHz, DCS 1800 MHz and PCS 1900 MHz. The modem utilizes the GPRS/GSM network for convenient and inexpensive data transfer from remote instruments, meters, computers or control systems in either live data or packet data acquisition. The GTM-201-RS232 has an integrated TCP/IP stack so that even simple controllers with serial communications ports can be connected to the modem without the need for special installation of drivers. The features of the GTM-201-RS232 allow a variety of PLC and PC applications to take advantage of SMS and GPRS connectivity. The voice interface allows these modems to be also applied to alarm systems with sounds. Moreover, the modem can integrate with PACs of ICP DAS to apply GPRS/GSM network in any remote control or acquisition systems.