Can I trust this probe's pH readings?

Not yet, from our field tests. A pH stuck near 7 can mean a dead electrode, and a 7.00 means no reading. Test the probe in neat vinegar and borax (see Field test) before relying on its pH.

What baud rate does the JXBS-3001-TR (7-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 (7-in-1) need?

DC 5–24 V (≤ 0.15 W (12 V DC)).

How do I change the JXBS-3001-TR (7-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 (7-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.

Does the JXBS-3001-TR (7-in-1) measure salinity and TDS?

The JXBS-3001-TR (7-in-1) reports moisture, temperature, EC, pH and N-P-K only — it does not report salinity and TDS. On the same RS-485 bus, add salinity: DFRobot SEN0601; TDS: DFRobot SEN0601.

How many Modbus registers does the JXBS-3001-TR (7-in-1) expose?

This guide documents 9 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, Nitrogen and Phosphorus.

Can the 7-in-1 be used only for pH and EC?

Yes. All supported fields may be collected while a particular dashboard or export concentrates on the series relevant to the installation.

Is this sensor suitable for a nutrient reservoir?

Do not infer liquid-immersion suitability from the RS-485 interface. Use this model only in the media and installation conditions stated by its manufacturer; choose liquid-rated probes for a reservoir.

Home / Sensors / JXBS-3001-TR (7-in-1)

JXCT · RS-485 sensor

Weihai JXCT Electronics

Updated 28 Oct 2026. pH from this JXBS-3001 probe family is low confidence. In our orchard, probes sent a fixed 7.00 or stayed near 7.7 and did not respond in test liquids. See the field test.

JXBS-3001-TR (7-in-1)

JXCT 7-in-1 with live N-P-K. pH scale 0.01; config at 0x0100/0x0101.

At a glance

The JXBS-3001-TR (7-in-1) is a 5-in-1 RS-485 soil probe reporting moisture, temperature, EC, pH and N-P-K over Modbus-RTU on RS-485 at 9600 bps, 8N1, on DC 5–24 V. This guide documents 9 registers, default Modbus address 1. It does not report salinity and TDS. For those on the same bus: salinity → DFRobot SEN0601; TDS → DFRobot SEN0601. Sankhya firmware profile: JXCT_7in1.

Sankhya Farms integration

Live JXCT N-P-K and root-zone readings in one dashboard

Sankhya Farms reads this JXBS-3001-TR 7-in-1 with the JXCT_7in1 profile. The node polls at 9600 baud, handles the scattered JXCT addresses and 0.01 pH scale, and sends moisture, signed temperature, EC, pH and the three live N-P-K words to the free cloud dashboard. It is not interchangeable with a ZTS decoder, even though the product descriptions use many of the same parameter names.

The combined record can support field comparisons, greenhouse and nursery trials, home-garden experiments or observation of a solid hydroponic substrate. A user can inspect a nutrient estimate alongside moisture and EC instead of treating it as a context-free number. The model documentation identifies the N-P-K values as live probe readings, unlike the write-in nutrient registers on certain ZTS-3002 devices. Even so, in-situ nutrient probes should be checked against reference samples and used as trend instruments where soil composition, moisture and salinity may affect response.

Native integration: one Sankhya profile converts the JXCT addresses into named dashboard series. No separate Node-RED flow or register-to-database mapping is required. See how nodes are configured.

Value lookup

How do I look up a JXCT 7-in-1 value?

pH is 0006H ×0.01; moisture and signed temperature are 0012H and 0013H ×0.1; EC is 0015H in µS/cm. Nitrogen, phosphorus and potassium are the direct mg/kg words at 001EH, 001FH and 0020H. Because these addresses are not contiguous, a robust poller either issues the appropriate ranges or reads them separately. Sankhya's profile performs that lookup and preserves the final units.

Can the 7-in-1 be used only for pH and EC?: Yes. All supported fields may be collected while a particular dashboard or export concentrates on the series relevant to the installation.
Is this sensor suitable for a nutrient reservoir?: Do not infer liquid-immersion suitability from the RS-485 interface. Use this model only in the media and installation conditions stated by its manufacturer; choose liquid-rated probes for a reservoir.

Quick reference

Bus & electrical specs

Protocol

Modbus-RTU over RS-485

Default baud

9600 bps

Serial format

8N1

Function codes

0x03

Supply voltage

DC 5–24 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_7in1

Specs sourced from: JXBS-3001 7-in-1 user manual (Ver 2.0).

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. Range 3-9 pH. Accuracy ±0.3 pH.
0012H	40019	Soil moisture	uint16	0.1	%RH	RO	Range 0-100%. Accuracy ±3% (0-53%), ±5% (53-100%).
0013H	40020	Soil temperature	int16	0.1	°C	RO	Range -40 to 80°C. Accuracy ±0.5°C. Negative in two's complement.
0015H	40022	Electrical conductivity	uint16	1	uS/cm	RO	Range 0-10000 uS/cm. Resolution 10 uS/cm.
001EH	40031	Nitrogen	uint16	1	mg/kg	RO	Range 0-1999 mg/kg. Accuracy ±2%FS. LIVE reading unlike ZTS family.
001FH	40032	Phosphorus	uint16	1	mg/kg	RO	Range 0-1999 mg/kg. LIVE reading.
0020H	40033	Potassium	uint16	1	mg/kg	RO	Range 0-1999 mg/kg. LIVE reading.
0100H	40257	Device address	uint16	1	—	RW	Range 0-255. Factory default 1.
0101H	40258	Baud rate	uint16	1	—	RW	Factory default 9600 bps. 2400=2400; 4800=4800; 9600=9600

Example poll

Worked query

# Read moisture + temperature request 01 03 00 12 00 02 64 0E response 01 03 04 02 92 FF 9B 5A 3D # moisture=65.8%, temperature=-10.1°C

# Read EC request 01 03 00 15 00 01 95 CE response 01 03 02 05 DC 8D 8D # EC=1500 uS/cm

# Read NPK (3 registers) request 01 03 00 1E 00 03 65 CD response 01 03 06 00 20 00 25 00 30 B1 6D # N=32 mg/kg, P=37 mg/kg, K=48 mg/kg

# Read pH request 01 03 00 06 00 01 64 0B response 01 03 02 01 34 B8 03 # pH=3.08

Field test

How far to trust this probe's pH

In our orchard, a pH stuck near 7 turned out to be a dead electrode. Until a probe passes the test below, treat its pH as low confidence. Its moisture and EC can still be useful.

What we saw (26 Oct 2026):

Exactly 7.00 is no reading. When the probe can't get a valid pH, it sends 7.00. Sankhya leaves those values out of every figure. One probe sent 7.00 every hour for more than a day.
A pH stuck near 7 doesn't move with the liquid. One probe read 7.71–7.75 in the soil and 7.70–7.78 in vinegar. Its moisture and EC followed the liquid, but its pH did not, so its electrode wasn't responding.
Register checks ruled out a wrong register. The working explanation is a failing electrode, which is why the test below uses liquids of known pH.

Test a JXBS-3001 pH probe

You need: neat white vinegar (pH about 2.4–3.4), borax at about one level teaspoon per litre of water (pH about 9.2), clean water for rinsing, two cups at least 10 cm deep, and a pen pH meter to check each liquid.

Keep both cups in the shade. In direct sun a cup reached 52 °C, and the readings jumped.
Power the probe for 5 minutes before the first reading. The manual gives no warm-up time, so we use the same wait as our field firmware.
Put the probe in the neat vinegar. Check the cup with the pen, then wait until the reading stops moving, about an hour. Note the value.
Rinse the probe in clean water. Put it in the borax, check the cup with the pen, wait until it settles, and note the value.
Read the result from the later reading in each cup, because the first can still be settling. A working probe reads close to 3 in the vinegar and close to 9 in the borax, so a swing of at least 4 pH is a pass. A dead probe stays between about 5.6 and 7.8, or at exactly 7.00 in both cups.
Don't use diluted vinegar. In hard water, a splash can sit anywhere from pH 4 to 7.

A pass means the electrode responds. Its pH is still low confidence until you check it against your pen readings with a two-point calibration. A fail means the electrode is dead: replace the probe, and don't use its pH in the meantime.

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. Range 0-255. Factory default 1.
Set the baud rate by writing register 0101H (PLC 40258). Values: 2400=2400, 4800=4800, 9600=9600. Factory default 9600 bps.
Power-cycle the probe after a configuration write for the change to take effect.

Field notes

Notes & caveats

JXCT 7-in-1. Unlike ZTS family, NPK here are LIVE probe readings. pH scale is 0.01 not 0.1. Config registers at 0x0100/0x0101 not 0x07D0/0x07D1. Default baud 9600 not 4800. Needs separate firmware profile from ZTS.

FAQ

Common questions

Can I trust this probe's pH readings?: Not yet, from our field tests. A pH stuck near 7 can mean a dead electrode, and a 7.00 means no reading. Test the probe in neat vinegar and borax (see Field test) before relying on its pH.
What baud rate does the JXBS-3001-TR (7-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 (7-in-1) need?: DC 5–24 V (≤ 0.15 W (12 V DC)).
How do I change the JXBS-3001-TR (7-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 (7-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.
Does the JXBS-3001-TR (7-in-1) measure salinity and TDS?: The JXBS-3001-TR (7-in-1) reports moisture, temperature, EC, pH and N-P-K only — it does not report salinity and TDS. On the same RS-485 bus, add salinity: DFRobot SEN0601; TDS: DFRobot SEN0601.
How many Modbus registers does the JXBS-3001-TR (7-in-1) expose?: This guide documents 9 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, Nitrogen and Phosphorus.

Alternatives

How this differs from similar models

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

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.