You have nine reasons to choose it! 1. The standard Modbus-TCP protocol! 2. The machine uses industrial-grade design standards, IP65 protection, high performance, high reliability, easy operation and setup, user-friendly! 3. The device supports 10 groups of user-defined data reporting features! 4. With four relay control output, corresponding to the four groups of alarm parameters set! 5. The alarm limit from the actual value of the user after the calibration, after the user calibration, the actual value can be read from the "input register"! 6. Alarm logic can take definite upper and lower limits, and set the dead zone to prevent the warning shake! 7. Set the relay control output is determined by the alarm, when an alarm occurs, the relay according to the set of "relay time" action! 8. Support HMI! 9. Provide engineering and design services software Demo! I. Introduction SMA-DTU-A1 equipment in accordance with industry-standard design, along with 4-20mA data sampling, alarm control output, real-time online data remote transmission capabilities. Support GPRS / GSM networks. With RS232, RS485 ports support standard Modbus-RTU protocol enables remote parameter configuration and real-time data measured by local communication port call or GPRS / GSM networks. Supports standard Modbus-TCP protocol. Second, the technical parameters 1, 4 analog inputs, the input signal 4-20mA. 2, 4 relay outputs, contact capacity 5A. 3, take the initiative to report configuration. 4, sample loss record. 5, you can set the sampling period. 6, serial, 1 RS232,1 way RS485, serial rate 1200bps-115200bps. 7,1 road GPRS / CDMA. 8, the working temperature: 0 ℃ ~ + 65 ℃, Humidity: 0 ~ 99% RH. Third, the basic parameters of the machine specification machine power supply 24VDC 2.5W Dimension Length: 158mm Width: 147.2mm Depth: 37.8mm (see size chart) controller parameters controller enclosure stainless steel housing Controller Power 24VDC internal real time clock Clock Operating temperature 0 ℃ ~ 65 ℃-frequency electrical properties of impulse voltage withstand 2KV 6KV static discharge 8KV (controller indirect discharge, metal shell direct discharge) surge 4KV differential mode 2KV common mode voltage range of 9-36V design life of 10 years Clock battery life of 12 years hardware interface 4-channel DC analog input signal 4-20mA RS485 1 channel, serial rate 1200bps-115200bps RS232 1 channel, serial rate 1200bps-115200bps GPRS / CDMA 1 4 channel relay output channels, contact capacity 5A