GSM (Global System for Mobile communication) offers a natural and easy platform for wireless automation, much more flexible and easier solution than for example traditional radio modems. The GSM-modem can be used to link PLC’s, data loggers, security and surveillance systems or for data acquisition. With the ability to call pre-set numbers or send/receive SMS-messages the GSM-modem is ideal for alarm monitoring and remote diagnostics for unmanned stations. The Westermo GSM-modem can communicate with other GSM-modems, traditional analogue modem and ISDN-adapters.