Application of RS485 for communication and synchronization in distributed electromagnetic exploration system

In order to solve the data communication and acquisition synchronization problem of distributed electromagnetic exploration system for specific application environment and measurement mode, master slave distributed communication network with dual channels is constructed based on RS485 bus, thus multi-station data is received by master station quickly. The communication bus and measuring circuit is isolated completely to eliminate common mode voltage interference and ensure the stability and stability of data communication. This paper puts forward an improved scheme for line synchronization that trigger signal for starting acquisition is transferred using RS485 bus. By testing and analysis, the linear relationship between delay time of trigger signal and distance is obtained. Field experimental results show that synchronization precision is able to satisfy the requirements of the measurement after compensating delay time.