GPRS DTU

This depends on the on-site signal coverage. GPRS is a 2G network. Although the bandwidth is low, the coverage radius of the base station is larger than 4G, and the penetration ability is stronger. In some remote mountainous areas, it is more stable. If you only transmit a small amount of sensor data and record one record every ten seconds, the bandwidth of GPRS is completely sufficient. If you will definitely upgrade to transmitting video or high-frequency data in the future, you can consider using 4G DTU directly, but many monitoring projects now still prefer GPRS because it is simple and reliable.

Kingmach's DTU has dual guarantees of hardware watchdog and software detection. After disconnection, it can usually detect and redial within 30 seconds. If the module crashes, the watchdog will forcefully restart the entire machine, and the recovery time is usually 1-2 minutes. The time can be adjusted through configuration, but it is recommended not to set it too short to avoid frequent reconnections that consume traffic and power.

A DTU usually only provides one serial port, either RS232 or RS485. If both interfaces are available on site, you can use a small module from 485 to 232, or choose a model that supports dual serial ports (need to confirm inventory). Kingmach's standard model is RS485, because the field wiring distance is long, 485 is more suitable. We can recommend the connection method based on your sensor list.

The heartbeat interval depends on your operator's policy. It is usually recommended to set it to 300 seconds (5 minutes), which can maintain continuous NAT mapping without causing too much traffic consumption. A heartbeat packet usually only has a few dozen bytes, which is only a few megabytes accumulated in a month, and can basically be ignored. However, if it is set too short, such as 30 seconds, the traffic will increase significantly. In a package with limited traffic, pay attention to controlling the interval.