Home / Sensors / ZTS-3002-TR-THNPKPH-N01
ZTS · RS-485 sensor
Zhaotaisheng
Moisture, temp, pH + write-in N-P-K (no live nutrient probe).
The ZTS-3002-TR-THNPKPH-N01 is a 4-in-1 RS-485 soil probe reporting moisture, temperature, pH and N-P-K over Modbus-RTU on RS-485 at 4800 bps, 8N1, on DC 4.5–30 V. This guide documents 8 registers, default Modbus address 1. It does not report EC, salinity and TDS. For those on the same bus: EC → ZTS-3000-TR-ECWS-N01; salinity → ZTS-3001-TR-ECTHPH-N01. Sankhya firmware profile: ZTS_5in1_noEC.
Sankhya Farms supports the ZTS-3002-TR-THNPKPH-N01 with the ZTS_5in1_noEC profile. The open-source node can collect its live moisture, signed temperature and pH readings and place them in the free cloud dashboard for history, comparison and remote observation. The profile also knows about the three N-P-K addresses, but the documented registers on this model are writable temporary values populated by an external instrument. They are not independent live nutrient measurements from the buried probe.
That distinction still leaves a practical sensor. Moisture, temperature and pH can answer routine questions in an orchard, vegetable bed, greenhouse pot, home garden or solid hydroponic media container: did water arrive, how quickly did the root zone dry, and did pH move after an intervention? A recirculating nutrient reservoir needs a liquid-rated probe instead. An operator may also write laboratory or handheld N-P-K results into the temporary fields to keep them beside the sensor history, provided the dashboard and downstream analysis identify their source. Sankhya's purpose here is not to turn stored numbers into measurements; it is to keep the data lineage clear.
Registers 0004H–0006H are temporary write-in fields. For live-probe N-P-K, choose a model whose manual expressly documents read-only nutrient sensing, such as the ZTS-3001 7-in-1 or the JXCT 7-in-1.
Moisture is at 0000H ×0.1%, signed temperature at 0001H ×0.1 °C, and pH at 0003H ×0.1. There is no EC word at 0002H on this variant. Although the N-P-K words appear at 0004H through 0006H, their read/write status is the clue that they are storage fields. Sankhya uses the model-specific map rather than assuming that a contiguous-looking register block has the same meaning as another ZTS product.
Specs sourced from: Official ZTS-3002-TR-N01 datasheet (R224073/R224074).
Function codes 0x03, 0x06 at 4800 bps, 8N1. Data registers are read with 0x03; configuration registers are written with 0x06. PLC column shows the 4xxxx Modbus holding-register convention.
| Register | PLC | Parameter | Type | Scale | Unit | R/W | Notes |
|---|---|---|---|---|---|---|---|
| 0000H | 40001 | Soil moisture | uint16 | 0.1 | % | RO | |
| 0001H | 40002 | Soil temperature | int16 | 0.1 | °C | RO | |
| 0003H | 40004 | pH | uint16 | 0.1 | pH | RO | |
| 0004H | 40005 | Nitrogen (temporary value) | uint16 | 1 | mg/kg | RW | NOT a live probe reading. |
| 0005H | 40006 | Phosphorus (temporary value) | uint16 | 1 | mg/kg | RW | NOT a live probe reading. |
| 0006H | 40007 | Potassium (temporary value) | uint16 | 1 | mg/kg | RW | NOT a live probe reading. |
| 07D0H | 42001 | Device address | uint16 | 1 | — | RW | |
| 07D1H | 42002 | Baud rate | uint16 | 1 | — | RW | 0=2400; 1=4800; 2=9600 |
This probe is configured over the same RS-485 bus using Modbus write commands (function code 0x06). Configure one device at a time on the bus.
Same as ECTHNPKPH variant but without EC register at 0002H. No 0002H register present in this variant.
How the ZTS-3002-TR-THNPKPH-N01 compares with the other RS-485 models in the Sankhya library. "Drop-in" means the same parameter set and the same register map, read by the same firmware profile.
| Model | Relationship | Measures | Baud | Difference |
|---|---|---|---|---|
| ZTS-3001-TR-ECTHNPKPH-N01 | Sibling | Moisture, Temperature, EC, pH, N-P-K, Salinity, TDS | 4800 | Adds EC, salinity and TDS. |
| ZTS-3001-TR-ECTHPH-N01 | Sibling | Moisture, Temperature, EC, pH, Salinity, TDS | 4800 | Adds EC, salinity and TDS, drops N-P-K. |
| ZTS-3000-TR-ECWS-N01 | Sibling | Moisture, Temperature, EC | 4800 | Adds EC, drops pH and N-P-K. |
| ZTS-3000-TR-WS-N01 | Sibling | Moisture, Temperature | 4800 | Drops pH and N-P-K. |
Every sensor on this page is in our RS-485 library. Pick your model, and the firmware-generation pipeline builds the Modbus (or ASCII) polling code for an ESP32-S3 node — no hand-coding the register math.
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