Katranji RS-NPK-N01-TR Soil Temperature and Moisture Transmitter Type 485 User Guide

June 15, 2024
katranji

Katranji RS-NPK-N01-TR Soil Temperature and Moisture Transmitter Type 485

Product Description

Product Description

The soil nitrogen, phosphorus, and potassium three-in-one fertility sensor is suitable for detecting the content of nitrogen, phosphorus, and potassium in the soil, and determining the fertility of the soil by detecting the content of nitrogen, phosphorus, and potassium in the soil, thereby facilitating the systematic assessment of the soil condition. Can be buried in the soil for a long time, resistant to long-term electrolysis, corrosion resistance, vacuum potting, completely waterproof. The sensor is widely used in soil nitrogen, phosphorus, potassium detection, precision agriculture, forestry, soil research, geological exploration, plant cultivation and other fields.

Features
  1. Low threshold, few steps, fast measurement, no reagents required, unlimited detection times.
  2. High measurement accuracy, fast response speed and good interchangeability.
  3. The electrode is made of a specially treated alloy material, which can withstand strong external force and is not easy to be damaged.
  4. Completely sealed, resistant to acid and alkali corrosion, can be buried in the soil for long-term dynamic testing.
  5. Probe insertion design ensures accurate measurement and reliable performance.
Technical Parameter
DC powered (default) DC 5-30V
Maximum power consumption ≤0.15W(@12V DC,25℃)
Operating temperature 0℃~55℃
NPK parameters Range
Resolution 1 mg/kg(mg/L)
Precision ±2%FS
Response time <1S
Protection class IP68
Probe material stainless steel
Sealing material Black flame retardant epoxy resin
Default cable length 2 meters, cable length can be customized
Dimensions 4515123mm
output signal RS485(Modbus protocol)
Product Model
RS- Company code
N- Soil nitrogen content transmitter
P Soil phosphorus content transmitter
K Soil potassium content transmitter
NPK Soil nitrogen, phosphorus, potassium three-in-one transmitter
N01- RS485 (Modbus-RTU protocol)
TR Soil testing enclosure

Dimensions

Equipment dimension drawing (unit: mm)

Instructions

Quick test method

Select a suitable measurement location, avoid stones, and ensure that the steel needle does not touch hard objects. Discard the topsoil according to the required measurement depth, and maintain the original tightness of the soil below. Hold the sensor vertically and insert it into the soil. It is not allowed to shake left and right, it is recommended to measure multiple times to find the average value within a small range of one measurement point.

Buried survey

Vertically dig a pit with a diameter of> 20cm, insert the sensor steel needle horizontally into the pit wall at
a predetermined depth, bury the pit tightly, and stabilize it for a period of time, then you can perform continuous measurement for several days, months, or even longer.

Precautions
  1. All steel needles must be inserted into the soil during measurement.
  2. Avoid direct sunlight on the sensor, which will cause excessive temperature. Pay attention to lightning protection in the field.
  3. Do not bend the steel needle violently, do not pull the sensor lead wire with force, and do not beat or violently hit the sensor.
  4. The protection grade of the sensor is IP68, which can soak the sensor in water.
  5. Due to the presence of radio frequency electromagnetic radiation in the air, it should not be energized in the air for a long time.

Equipment installation instructions

Check before equipment installation

Equipment List:

  • 1 sensor device
  • Certificate of conformity, warranty card
Interface Description

Wide voltage power input can be 5 ~ 30V. When wiring the 485 signal line, pay attention that the two lines A and B cannot be reversed, and the addresses between multiple devices on the bus must not conflict.

Wiring instructions
Thread color Description Note
brown Power supply 5~30V DC
black Negative power GND
yellow 485-A 485-A
blue 485-B 485-B

Configuration software installation and use

Software selection

Open the package and select “Debugging Software” “485 Parameter Configuration Software” and find Just open it.

parameter settings
  1. Select the correct COM port (check the COM port in “My Computer-Properties-Device Manager-Port”). The following figure lists several different 485 converter driver names.

  2. Connect only one device and power on. Click the software to test the baud rate. The software will test the baud rate and address of the current device. The default baud rate is 4800bit / s and the default address is 0x01.

  3. Modify the address and baud rate according to the needs of use, and can query the current function status of the device.

  4. If the test is unsuccessful, please recheck the equipment wiring and 485 driver installation.

letter of agreement

Basic communication parameters
Code  8-bit binary
Data bit 8-bit
Parity bit NO
Stop bit 1-bit

Error
checking| CRC (Redundant cyclic code)
Baud rate| Can be set, factory default is 4800bit / s

Data frame format definition

Modbus-RTU communication protocol is adopted, the format is as follows:
Initial structure ≥ 4 bytes of time
Address code = 1 byte
Function code = 1 byte
Data area = N bytes
Error check = 16-bit CRC
Ending structure ≥ 4 bytes of time

Address code: It is the address of the transmitter, which is unique in the communication network (factory default0x01).
Function code: Function instruction of the command sent by the host.
Data area: The data area is the specific communication data. Note that the high byte of the 16bits data comesfirst!
CRC code: two-byte check code.

Host inquiry frame structure:

address

code

| function

code

| Register start

address

| Register length| Checksum low

byte

| Checksum high

byte

---|---|---|---|---|---
1byte| 1byte| 2byte| 2byte| 1byte| 1byte

Slave response frame structure:

address code| function code| Number of valid bytes| Data area| Data area 2| Data N area| Checksum low byte| Checksum high byte
---|---|---|---|---|---|---|---
1byte| 1byte| 1byte| 2byte| 2byte| 2byte| 1byte| 1byte

Register address
Register address PLC or configuration address content operating Definition
001E H 40031 (Decimal) Nitrogen content Read-only Real-time nitrogen

content
001F H| 40032 (Decimal)| Phosphorus content| Read-only| Real-time value of

phosphorus content

0020 H| 40033 (Decimal)| Potassium content| Read-only| Real-time potassium content
03E8 H| 41001 (Decimal)| Nitrogen content coefficient High sixteen| Read and write| actual value (IEEE754 standard floating point)
03E9 H| 41002 (Decimal)| Nitrogen content coefficient Lower sixteen| Read and write|
03EA H| 41003 (Decimal)| Calibration value of nitrogen content| Read and

write

| Integer
03F2 H| 41011 (Decimal)| Phosphorus content coefficient High sixteen| Read and write| actual value (IEEE754 standard floating point)
03F3 H| 41012 (Decimal)| Phosphorus content coefficient Lower sixteen| Read and write|
03F4 H| 41013 (Decimal)| Calibration value of phosphorus content| Read and write| Integer
03FC H| 41021 (Decimal)| Potassium content coefficient High sixteen| Read and write| actual value (IEEE754 standard floating point)
03FD H| 41022 (Decimal)| Potassium content coefficient Lower sixteen| Read and write|
03FE H| 41023 (Decimal)| Calibration of potassium| Read and write| Integer
07D0 H| 42001 (Decimal)| Device address| Read and write| 1~254(Factory default1)
07D1 H| 42002 (Decimal)|  Device baud rate| Read and write| 0 for 2400

1 for 4800

2 for 9600

Communication protocol example and explanation

Example: Read the real-time value of nitrogen content at device address 0x01

Inquiry frame

address code| function code| starting address| Data length| Checksum low byte| Checksum high byte
---|---|---|---|---|---
0x01| 0x03| 0x00 0x1E| 0x00 0x01| 0xE4| 0x0C

Response frame

address code| function code| Returns the number of valid bytes| Nitrogen content| Checksum low byte| Checksum high byte
---|---|---|---|---|---
0x01| 0x03| 0x02| 0x00 0x20| 0xB9| 0x9C

Calculation of phosphorus content:

Phosphorus content: 0025 H (hexadecimal) = 37 => phosphorus = 37mg / kg

Example: Read the real-time value of potassium content at device address 0x01

Inquiry frame

address code| function code| starting address| Data length| Checksum low byte| Checksum high byte
---|---|---|---|---|---
0x01| 0x03| 0x00 0x20| 0x00 0x01| 0x85| 0xC0

Response frame

Response frame

|

Response frame

|

Response frame

|

Response frame

|

Response frame

|

Response frame

---|---|---|---|---|---

Response frame

|

Response frame

| Response frame|

Response frame

|

Responsae frame

| Response frame

Calculation of potassium content:

Potassium content: 0030 H (hexadecimal) = 48 = > potassium = 48mg / kg

Common problems and solutions

Device cannot be connected to PLC or computer

possible reason:

  1. The computer has multiple COM ports, and the selected port is incorrect.
  2. The device address is wrong, or there are devices with duplicate addresses (the factory defaults are all 0x01).
  3. Baud rate, check mode, data bit, stop bit error.
  4. The 485 bus is disconnected, or the A and B wires are reversed.
  5. Too many devices or wiring is too long, you should supply power nearby, add 485 booster, and increase 120Ω terminal resistance.
  6. The USB to 485 driver is not installed or damaged.
  7. The equipment is damaged.

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