Feature:

• Easy to measure, not only for professionals, but also for non-professionals, just insert the instrument into the soil to measure.
• High precision, fast speed measurement, accuracy up to within 2%, and increased stability, more accurate data.
• The resolution is up to 1mg/kg (mg/l), on-site quick inspection, easy to carry, and can be read by inserting into the soil.
• Portable measurement, accurate grasp of the soil fertility status, the user can measure the soil condition at any time, according to the soil condition, the soil fertility can be balanced to achieve a suitable growth environment for the plant.
• The sensor uses high quality chip, low power consumption, high sensitivity and stable signal.
• IP68 grade waterproof and dustproof, to ensure the normal operation of components for a long time. Good sealing performance to prevent moisture from entering the interior of the instrument.
• High quality probe, rust resistance, electrolytic resistance, salt and alkali corrosion resistance, to ensure the long-term operation of the probe part. Therefore, it is suitable for all kinds of soil.
• Suitable for agricultural production, greenhouse breeding, orchard nursery, soil research.
• It is suitable for the detection of alkaline soil, acid soil, substrate soil, seedling bed soil, coconut bran soil.

Specification:

• Condition: 100% Brand New
• Item Type: Soil NPK Sensor
• Material: ABS
• Color: As shown in the picture
• Length(not include cable): Approx.11.5cm/4.5in
• Width: Approx.4cm/1.6in
• Weight: Approx.203g/7.2oz
• Measuring Range: 0-1999mg/kg
• Working Humidity: 5 to 95% (relative humidity), no condensation
• Measurement Accuracy: ±2%F.s
• Resolution: 1mg/kg (mg/l)
• Baud Rate: 2400/4800/9600
• Response Time (T90, seconds): less than 10
• Communication Port: RS485
• Working Temperature: 5 to 45 ° C
• Power Supply: 12V-24V DC
• Protection Class: IP68

User Manual

Chapter 1 Product Introduction

1.1 Product Overview

Soil nitrogen, phosphorus and potassium sensor is suitable for detecting the content of nitrogen, phosphorus and potassium in soil. It can judge the fertility degree of soil by detecting the content of nitrogen, phosphorus and potassium in soil, thus facilitating the systematic evaluation of soil conditions by customers. .

1.2 Scope of Application

It is widely used in paddy field, greenhouse planting, rice, vegetable planting, orchard nursery, flower and soil research, etc.

1.3 Measurement parameters

1.4 System Framework Diagram

The sensor can be connected and used separately. Firstly, it is powered by 12V DC power supply. The device can directly connect the PLC with 485 interface, and can connect the single chip through 485 interface chip. The MCU and PLC can be programmed by the Modbus protocol specified later to cooperate with the sensor. At the same time, the computer can be connected by using USB to 485. The sensor configuration tool provided by our company is used to configure and test.

Chapter 2 Hardware Connections

2.1 Pre-installation inspection of equipment

Check the device inventory before installing it.

2.2 Interface Description

The power interface is wide voltage power supply input 12-24V can be. Analog products should pay attention to the positive and negative signal lines, and do not connect the positive and negative current/voltage signal lines.

Notes: Please be careful not to mistake the wiring sequence, the wrong

wiring will lead to equipment burnout.

The factory defaults to provide 0.6m long wire, customers can extend the wire or sequential wiring as needed.

Note that there is no yellow line in the possible sequence in some factory batches. At this time, the gray line replaces the yellow line equally.

2.3 Surface Survey Method

Choose the appropriate measuring location, avoid stones, ensure that the steel needle will not touch hard objects, according to the required measuring depth, throw away the surface soil, maintain the original tightness of the soil below, grasp the sensor vertically inserted into the soil, insertion can not sway left and right, a small range of measurement points suggested that the average value be measured many times.

2.4 Buried Survey Method

When a pit with diameter > 20 cm is excavated vertically, the sensor steel needle is inserted horizontally into the wall of the pit at a given depth, and the pit is landfilled tightly. After stabilizing for a period of time, it can be measured and recorded continuously for several days, months or even longer.

2.5 Notes

1. All steel needles must be inserted into the soil when measuring.

2. Avoid intense sunlight directly irradiating the sensor and causing excessive temperature. Attention should be paid to lightning protection in field use.

3. Don't bend the steel needle violently, pull the sensor lead-out wire forcefully, and don't hit or hit the sensor violently.

4. Sensor protection level IP68 can soak the whole sensor in water.

5. Because of the existence of radio frequency electromagnetic radiation in the air, it is not suitable to be electrified for a long time in the air.

Chapter 3 Installation and Use of Configuration Software

Our company provides a complete set of "sensor monitoring software", which can easily use computers to read sensor parameters, while flexibly modifying the device ID and address of the sensor.

3.1 Sensor Access to Computer

After connecting the sensor to 485 via USB and providing power, you can see the correct COM port in the computer ("My Computer - Attribute - Device Manager - Port").

As shown in the figure above, your serial number is COM10 at this time. Please remember this serial number. You need to fill in this serial number in the sensor monitoring software.

If no COM port is found in the device manager, it means that you have not inserted USB to 485 or installed the driver correctly. Please contact the technician for help.

3.3 Modify baud rate and device ID

In the case of disconnecting the device, click on the device baud rate and setting address in the communication settings to complete the relevant settings. Please note that after setting, please restart the device, and then "automatically get the current baud rate and address" can find that the address and baud rate have changed to the address and baud rate you need.

If you need to use the Modbus instruction to modify the baud rate and address, you can see the appendix "How to use the Modbus instruction to modify the baud rate and address". Chapter 4 Communication Protocol

4.1 Basic Communication Parameters

parameter: content

Code: 8-bit binary

Data bits: 8 place

Parity bit: nothing

Stop bit: 1 place

Error Check: CRC (Redundant Cyclic Code)

baud rate: 2400 bps/4800 bps/9600 BPS can be set, default is 9600 BPS

4.2 Data frame format definition

Modbus-RTU protocol is adopted in the following format:

Initial structure >= 4 bytes of time

Address code = 1 byte

Function code = 1 byte

Data area = N bytes

Error Check = 16 Bit CRC Code

End structure >= 4 bytes of time

Address code: The address of the transmitter is unique in the inquiry network (factory default 0x01).

Function code: The instruction function prompt issued by the host computer, this transmitter only uses function code 0x03 (read register data).

Data area: The data area is the specific call area. Note that the high bytes of 16bits data are in front of each other.

CRC Code: Two-byte Check Code