Can more than one sensor be connected to the security digital input?
Yes. Sensors like motion sensors, magnetic contacts, smoke sensors, CO2 sensors, water leakage sensors use normally closed contacts. Several this type sensors etc. can be connected serially to put in one digital input of device. Any of contact status change gives alarm to the device corresponding input.
Is there 3G or 4G module instead of GPRS ?
No. GPRS communication is used for SMS and in case ethernet connection is broken. Since data length which is transferred between server and device is very small, no need to use high speed. GPRS modul is fast enough for its purpose and much less cost.
transparent serial port (UART)?
Transparent serial ports are used to communicate with other equipments (DCE) by RS-232 port remotely. Smart Telemetry has two transparent serial ports. Those ports act as Remote Server's own serial ports.
When Remote Server sends data to Smart Telemetry for transparent serial port, Smart Telemetry sends that data to one of transparent serial ports which is connected to controlled equipment (DCE) and vice versa.
How does camera snapshot control is used? What kind of camera should be used?
When Smart Telemetry changes its status to ALARM (security input is activated when device is ARMed), device sends snapshot order to camera with predefined periods by dry-contacts.
IP camera takes photos and sends picture data to FTP server which is defined in camera settings when gets shot order by dry contact input.
Camera should be IP camera which can send picture to FTP server and has digital input for shot order.