CO2 Sensor Module Detector Carbon Dioxide Temperature Humidity 3-In-1 Transmitter 485 Condition: Item Type: CO2 Transmitter Material: PVC Power Supply: 10-30V DC Average Current: <85mA Measuring Range: 400-5000PPm CO2 Accuracy: ± (40ppm + 3% F·S) (25 ℃) Temperature Measurement Range: -40 ℃ -80 ℃ Temperature Accuracy: ± 0.5 ℃ Humidity Measurement Range: 0-100% RH Humidity Accuracy: ± 3% RH Working Temperature: -40 ℃-+ 60 ℃ Operating Humidity: 0% RH-80% RH Stability: <2% F·S Non-Linearity: <1% F·S Data Update Time: 2s Warm-Up Time: 2min (Available), 10min (Maximum Accuracy) Temperature Effect: Comes with Temperature Compensation Output Signal: 485 Protection Level: IP65 Weight: Approx. 177g / 6.2oz Size: Approx. 13x11.7x4.2cm / 5.1x4.6x1.7in Interface Description: Wide voltage power input 10-30V. When connecting 485 signal line, note that A / B lines cannot be connected reversely, and the addresses of multiple devices on the bus cannot conflict.   Line Color Description Power Supply Brown Power Supply (10 - 30V DC) Black Negative Power Communication Yellow 485-A Blue 485-B Basic Communication Parameters: Code 8-Bit Binary Data Bit 8-Bit Parity Bit No Stop Bit 1 Person Error Checking CRC (Redundant Cyclic Code) Baud Rate 2400bit / s, 4800bit / s, 9600 bit / s can be set, the factory default is 4800bit / s Common Problems and Solutions: Possible reasons for the tool not being able to connect to the PLC or computer: 1. The computer has multiple COM ports. The selected port is incorrect. 2. The address of the tool is wrong, or there are devices with duplicate addresses (factory default is 1). 3. Baud rate, verification mode, data bit, stop bit error. 4. The host polling interval and waiting time are too short, which need to be set above 200ms. 5.485 bus is disconnected, or a and B wires are connected reversely. 6. If the number of equipment is too large or the wiring is too long, the power shall be supplied nearby, 485 intensifier shall be added, and 120 Ω terminal resistance shall be added at the same time. 7. The usb-485 drive is not installed or damaged. 8. The equipment is damaged.