What baud rate does the JXBS-3001-TR (4-in-1) use by default?

9600 bps, 8N1. It is a Modbus-RTU slave; default address 1.

What supply voltage does the JXBS-3001-TR (4-in-1) need?

DC 12–24 V (≤ 0.15 W (12 V DC)).

How do I change the JXBS-3001-TR (4-in-1) Modbus address?

Write the device-address register with function code 0x06, one device on the bus at a time, then power-cycle. See the Configuration section above.

Is the JXBS-3001-TR (4-in-1) compatible with the Sankhya platform?

Yes — it is in the Sankhya RS-485 sensor library and the firmware-generation pipeline can produce node firmware for it.

What does the JXBS-3001-TR (4-in-1) not measure?

The JXBS-3001-TR (4-in-1) reports moisture, temperature, EC and pH only — it does not report N-P-K, salinity and TDS. On the same RS-485 bus, add N-P-K: JXBS-3001-TR (7-in-1); salinity: DFRobot SEN0603; TDS: DFRobot SEN0603.

How many Modbus registers does the JXBS-3001-TR (4-in-1) expose?

This guide documents 6 registers, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include pH, Soil moisture, Soil temperature, Electrical conductivity, Device address and Baud rate.

Why does a generic ZTS decoder give implausible values?

JXCT uses different addresses, a different factory baud and a different pH scale. A response can pass its CRC and still be semantically wrong if decoded with the wrong family profile.

Does the 4-in-1 report N-P-K?

No. The N-P-K addresses belong to the 7-in-1 variant and are absent from this model's documented hardware.

Home / Sensors / JXBS-3001-TR (4-in-1)

JXCT · RS-485 sensor

Weihai JXCT Electronics

JXBS-3001-TR (4-in-1)

JXCT 4-in-1 — moisture, temp, EC, pH. Distinct register family (baud 9600).

✓ Verified for SankhyaMoistureTemperatureECpHVerification 0.95 · datasheet-confirmed

At a glance

The JXBS-3001-TR (4-in-1) is a 4-in-1 RS-485 soil probe reporting moisture, temperature, EC and pH over Modbus-RTU on RS-485 at 9600 bps, 8N1, on DC 12–24 V. This guide documents 6 registers, default Modbus address 1. It does not report N-P-K, salinity and TDS. For those on the same bus: N-P-K → JXBS-3001-TR (7-in-1); salinity → DFRobot SEN0603. Sankhya firmware profile: JXCT_4in1.

Sankhya Farms integration

A JXCT dashboard profile that respects its unusual register layout

The JXBS-3001-TR 4-in-1 cannot safely be decoded by borrowing a ZTS example. Sankhya Farms uses the dedicated JXCT_4in1 profile at 9600 baud: pH, moisture, signed temperature and EC come from scattered addresses, and pH uses a 0.01 scale rather than the 0.1 scale common in the ZTS family. The open-source node applies those rules before sending the four values to the free cloud dashboard.

Once decoded correctly, the probe can provide a useful root-zone record in an orchard, greenhouse, nursery, vegetable plot, home garden, landscape bed or substrate container. It is particularly convenient when someone wants to look up whether watering altered both moisture and EC, or whether pH remained stable during the same interval. Sankhya can be used solely as a remote observer and historical logger; connecting the sensor does not imply automatic dosing. In hydroponics, this buried sensor is most appropriate for compatible solid media. A reservoir needs liquid-rated instrumentation even if it also communicates over 12 V RS-485.

Why the named profile matters: the sensor's data registers are 0006H, 0012H, 0013H and 0015H, not one contiguous block from zero. Review RS-485 bus wiring.

Value lookup

Where do I find pH, moisture, temperature and EC?

Use function code 0x03. pH is at 0006H ×0.01, moisture at 0012H ×0.1%, signed temperature at 0013H ×0.1 °C, and EC at 0015H in µS/cm. Device address and baud are configured at 0100H and 0101H. A raw pH word of 635 therefore means pH 6.35, not 63.5. Sankhya performs the model-specific lookup so charts receive the correct scale.

Why does a generic ZTS decoder give implausible values?: JXCT uses different addresses, a different factory baud and a different pH scale. A response can pass its CRC and still be semantically wrong if decoded with the wrong family profile.
Does the 4-in-1 report N-P-K?: No. The N-P-K addresses belong to the 7-in-1 variant and are absent from this model's documented hardware.

Quick reference

Bus & electrical specs

Protocol

Modbus-RTU over RS-485

Default baud

9600 bps

Serial format

8N1

Function codes

0x03

Supply voltage

DC 12–24 V

Power

≤ 0.15 W (12 V DC)

Default address

Ingress / housing

IP68

Probe / element

316L stainless steel

Operating temp.

−40 to +80 °C (probe)

Firmware profile

JXCT_4in1

Specs sourced from: Official JXBS-3001-TR datasheet (R208894) and JXCT manuals.

Modbus-RTU register map

Function codes 0x03 at 9600 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
0006H	40007	pH	uint16	0.01	pH	RO	Scale factor 0.01 — different from ZTS family which uses 0.1.
0012H	40019	Soil moisture	uint16	0.1	%RH	RO
0013H	40020	Soil temperature	int16	0.1	°C	RO	Negative in two's complement.
0015H	40022	Electrical conductivity	uint16	1	uS/cm	RO
0100H	40257	Device address	uint16	1	—	RW	DIFFERENT from ZTS family — address register is at 0x0100, not 0x07D0.
0101H	40258	Baud rate	uint16	1	—	RW	DIFFERENT from ZTS family — baud register at 0x0101, not 0x07D1. Factory default 9600. 2400=2400; 4800=4800; 9600=9600

Example poll

Worked query

Configuration

Changing address & baud rate

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.

Set the Modbus slave address by writing register 0100H (PLC 40257) with function code 0x06. DIFFERENT from ZTS family — address register is at 0x0100, not 0x07D0.
Set the baud rate by writing register 0101H (PLC 40258). Values: 2400=2400, 4800=4800, 9600=9600. DIFFERENT from ZTS family — baud register at 0x0101, not 0x07D1. Factory default 9600.
Power-cycle the probe after a configuration write for the change to take effect.

Field notes

Notes & caveats

Upgraded to 0.95 — official JXBS-3001-TR Ver1.1 manual uploaded (R208894, Weihai JXCT Electronics). The 4:1 variant is a subset of the 7:1: same register addresses confirmed — 0006H=pH(×0.01), 0012H=moisture(×0.1%RH), 0013H=temperature(×0.1°C), 0015H=EC(1us/cm), config at 0100H/0101H. NPK registers (001EH-0020H) simply absent on 4:1 hardware. Default baud 9600 confirmed. Power 12-24V DC confirmed. JXCT register layout remains fundamentally different from ZTS/SN family — pH scale 0.01 vs ZTS 0.1, moisture at 0012H not 0000H, config at 0100H not 07D0H.

FAQ

Common questions

What baud rate does the JXBS-3001-TR (4-in-1) use by default?: 9600 bps, 8N1. It is a Modbus-RTU slave; default address 1.
What supply voltage does the JXBS-3001-TR (4-in-1) need?: DC 12–24 V (≤ 0.15 W (12 V DC)).
How do I change the JXBS-3001-TR (4-in-1) Modbus address?: Write the device-address register with function code 0x06, one device on the bus at a time, then power-cycle. See the Configuration section above.
Is the JXBS-3001-TR (4-in-1) compatible with the Sankhya platform?: Yes — it is in the Sankhya RS-485 sensor library and the firmware-generation pipeline can produce node firmware for it.
What does the JXBS-3001-TR (4-in-1) not measure?: The JXBS-3001-TR (4-in-1) reports moisture, temperature, EC and pH only — it does not report N-P-K, salinity and TDS. On the same RS-485 bus, add N-P-K: JXBS-3001-TR (7-in-1); salinity: DFRobot SEN0603; TDS: DFRobot SEN0603.
How many Modbus registers does the JXBS-3001-TR (4-in-1) expose?: This guide documents 6 registers, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include pH, Soil moisture, Soil temperature, Electrical conductivity, Device address and Baud rate.

Alternatives

How this differs from similar models

How the JXBS-3001-TR (4-in-1) 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
JXBS-3001-TR (7-in-1)	Sibling	Moisture, Temperature, EC, pH, N-P-K	9600	Adds N-P-K.
JXBS-3001-PH-RS	Sibling	pH	9600	Drops moisture, temperature and EC.
JXBS-3001-NPK-RS	Sibling	N-P-K	9600	Adds N-P-K, drops moisture, temperature, EC and pH.

Same family

Related JXCT sensors

Run this sensor on a Sankhya node

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.