HD53GSM is a wireless quad-band GSM/GPRS modem. The module is controlled via
standard RS232 serial interface and AT commands. It features:
– SIM card slot,
– SMA antenna connector,
– power line connector with remote on/off line,
– two status LED: the POWER LED is switched on when the GSM is powered,
the NET LED indicates the connection status to the GSM net,
– RS232 Sub-D 9-pin connector.