A LoRa transmitter and receiver refers to a pair of devices that utilize LoRa technology for wireless communication. These devices can be used to establish a long-range, low-power communication link without the need for internet or GSM connectivity. They are commonly used in various applications such as agriculture and industry. The transmitter sends data wirelessly, while the receiver receives and decodes the transmitted data. The devices can be connected using either SPI or UART connections, with SPI being recommended for ease of connection. There are also ready-made modules available for purchase, such as the G-NiceRF LORA1276 915mhz 100mW SPI SX1276 LoRa Transmitter and Receiver Module.
What is the difference between the lora transmitter and 4G/NB-IOT transmitter ? #
Generally speaking, lora transmitter which communicate with the lora receiver gateway with limited transmission distance by lora multiple nodes, however, the 4G and NB-IOT is transmitter by the base station which no need to work with a gateway, the data transmission by the SIM card. you can lear more as follows:
Which kind of battery used for Sentec lora transmitter ? #
SenTec lora transmitter used 38000mAh disposable lithium battery or 76000mAh disposable lithium battery options.
What is the general battery life of the lora transmitter ？ #
The data collection frequency is different, and the lora transmitter battery life is different. For details, please refer to the following:
1 minute (60 seconds) = estimated 1-2 years
5 minutes (300 seconds) = estimated 2 years
10 minutes (600 seconds) = estimated 2-3 years
30 minutes (1800 seconds) = estimated 3 years
1 hour (3600 seconds) = estimated 3~4 years
Note: Considering the battery usage environment, time and power consumption loss of the battery itself, the above time may be different from the actual usage time. Please refer to the actual usage time for details.
How to deal with the lora transmitter Zero migration ? #
Lora transmitter Zero-point migration processing method: Press W1 several times in a row, wait until 95 appears in the upper left corner, then press w2, then press zero, and wait until the backlight on the meter is turned off.
⚠️Note: When the zero point is migrated, do not use the magnet to brush first. The purpose of the magnet brush is to restart the meter
PM450 troubleshooting #
When the meter does not work normally, the user can refer to the following table for simple maintenance. If the fault cannot be eliminated, please contact us.
| Phenomenon | Cause Analysis | Solutions |
| Meter no display | Battery is dead | Replace the battery |
| The host computer does not receive data. | Inconsistent wireless parameters | Set the meter’s wireless channel and ID to be consistent with the host computer. |
| Low pressure | Pressure hole is blocked | Remove the instrument and clean the pressure hole |
Why does the lora transmitter jump before (-99999) and the actual value? #
Generally, SenTec lora transmitter displays -99999, indicating that the instrument has a communication failure or the instrument is disconnected and removed. This is a feature, not a glitch.
The initial default of the wireless gateway RTU corresponding register is not connected to the pressure transmitter -10000. After connecting to the pressure transmitter, the communication data will be saved normally. If the pressure transmitter communication failure occurs, the register number will change to -99999, such as normal communication. When a pressure transmitter is disconnected, the gateway will change the register value to -99999 at this time, indicating that the communication of the transmitter is disconnected, and the normal reading will continue after the communication is restored normally.
If the communication distance between the pressure transmitter and the gateway is relatively long, or if there are many pressure transmitters connected to the gateway, -99999 may appear, because the response rate of lora is relatively slow, and if there are too many pressure transmitters When the transmitter needs to respond to the situation, if the data collection interval is too short, some transmitters will not receive the response from the gateway and will lead to disconnection.
Therefore, in this case, if the RTU gateway needs to be connected to more pressure transmitters, we recommend extending the data collection time interval, such as modifying 180S. Or increase the number of RTU gateways to ensure faster data collection time.
Of course, if you don’t want the -99999 drop notification function, we can also block it. In this way, even if the instrument is disconnected or the instrument is removed. The gateway will only keep the data from the last communication.
What is the difference between lora transmitter screen reading refresh time VS RTU gateway receiver Data acquisition interval #
1. The lora transmitter refresh time of the screen reading of the pressure transmitter, the factory default is 60S, and the customer cannot modify it by himself. In general, the screen refresh time is less than or equal to the upload time. For example, the screen refresh time of the pressure transmitter is set to 120s, but if the RTU data collection interval is set to 60s, the screen refresh time of the pressure transmitter head will be reset by the RTU. , that is, 120s will be modified to 60s.
2. RTU gateway receiver data acquisition interval can be modified by customers within 1 Minute-1 Day. Check more here
Why sometime the lora transmitters reading high values but after reset its showing actual values #
Generally, Lora transmitter will go to sleep, the last data collected before the actual sleep is relatively large, but the actual pressure will change before the end of the sleep, which is why the real-time pressure value will be displayed when the meter is reset.
This acquisition display is related to the screen refresh time. The transmitter does not always refresh the screen, but updates the data every time the set screen refresh time is up.
Why we only get the signal properly up to 300 meters only in open space ? #
The communication distance is related to the air speed. The air speed is divided into lv1-6 levels. The larger the number, the lower the power, the lower the power consumption and the closer the transmission distance. Our factory default setting is LV3 level. At LV3 rate, if the RTU gateway is connected to 20pcs PM450 transmitters, the communication distance can reach 800 meters.
If the number of lora transmitters connected to the RTU gateway receiver is too large, the communication transmission distance may be reduced.
Of course, the air rate level can me modified by yourself according to your actual transmission distance. However, because the transmission distance is related to power consumption, after the output distance is increased, the power consumption becomes larger, and the battery of the transmitter is consumed faster.
