Wall Mounted Carbon Monoxide Transmitter Temperature Humidity CO Gas Sensor Detector 485 Condition: Item Type: CO Transmitter Material: PVC Protection Grade: IP65 Range: 0-1000ppm Weight: Approx. 181g / 6.4oz Size: Approx. 11.7x11.5x4cm / 4.6x4.5x1.6in Main Technology Parameters: Power Supply 10 - 30V DC Average Power 0.18W Output Signal 485 Temperature Measurement Range -40 ℃ - + 80 ℃ Humidity Measurement Range 0 - 100% RH Temperature Accuracy ± 0.5 ℃ Humidity Accuracy 3% RH CO Resolution 1ppm CO Accuracy ± 3% FS Zero Drift ± 3ppm Operating Temperature -20 - 50 ℃ Working Humidity 15 - 90% RH non-condensing Stability ≤2% signal value / month Response Time ≤30S Repeatability ≤2% output value Pressure Range 90 - 110Kpa All the above specifications and parameters are measured under the environmental conditions: temperature 20 ℃, relative humidity 50% RH, 1 atmospheric pressure, and the maximum gas concentration to be measured does not exceed the range of the sensor. Interface Description:   Line Color Description Power Supply Brown Power Supply (10 - 30V DC) Black Negative Power Communication Yellow 485-A Blue 485-B 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 to 485 drive is not installed or damaged. 8. The equipment is damaged.