... portUSB portTransmission5VDC,12VDC,24VDC auxiliary power supply for sensors. USB port: plug and play. Support 1GB,2GB,..USB flash driveCommunication: RS485,RS232, MODBUS ... kept byFLASH MEMORY, which can be kept forever when the power is off. The recorder can still run accurately when the ... power is off by using hard clock in recorder.Dimension:144* ...