What baud rate does the JXBS-3001-PH-RS use by default?

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

What supply voltage does the JXBS-3001-PH-RS need?

DC 12–24 V (≤ 0.15 W (12 V DC)).

How do I change the JXBS-3001-PH-RS 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-PH-RS 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-PH-RS not measure?

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

How many Modbus registers does the JXBS-3001-PH-RS expose?

This guide documents 4 registers, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include Low-precision pH, High-precision pH, Device address and Baud rate.

Home / Sensors / JXBS-3001-PH-RS

JXCT · RS-485 sensor

Weihai JXCT Electronics

JXBS-3001-PH-RS

JXCT standalone soil pH probe (pH scale 0.01).

✓ Verified for SankhyapHVerification 0.95 · datasheet-confirmed

At a glance

The JXBS-3001-PH-RS is a single-parameter RS-485 soil probe reporting pH over Modbus-RTU on RS-485 at 9600 bps, 8N1, on DC 12–24 V. This guide documents 4 registers, default Modbus address 1. It does not report moisture, temperature, EC and others. For those on the same bus: moisture → JXBS-3001-TR (4-in-1); temperature → JXBS-3001-TR (4-in-1). Sankhya firmware profile: JXCT_pH_only.

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_pH_only

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	Low-precision pH	uint16	0.01	pH	RO	Scale 0.01. Range 3-9 pH. Accuracy ±0.3 pH. Response time ≤15s.
000DH	40014	High-precision pH	uint16	0.01	pH	RO	Scale 0.01. Higher precision variant of pH reading. Use this register for primary measurement.
0100H	40257	Device address	uint16	1	—	RW	Range 0-252. 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 high-precision pH at 000DH request 01 03 00 0D 00 01 15 C9 response 01 03 02 00 47 D8 15 # 0047H=71 => pH=7.1

# Read low-precision pH at 0006H request 01 03 00 06 00 01 64 0B response 01 03 02 01 34 D8 15 # 0134H=308 => pH=3.08

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 0-252. 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

Confirmed from official JXCT PDF (v2.0, 2020-10-24). Default baud 9600 (not 4800). Power 12-24V (not 5-24V). Long-term stability ≤5%/year. Two pH registers — use 000DH (high precision) as primary. JXCT config register layout (0100H/0101H) confirmed.

FAQ

Common questions

What baud rate does the JXBS-3001-PH-RS use by default?: 9600 bps, 8N1. It is a Modbus-RTU slave; default address 1.
What supply voltage does the JXBS-3001-PH-RS need?: DC 12–24 V (≤ 0.15 W (12 V DC)).
How do I change the JXBS-3001-PH-RS 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-PH-RS 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-PH-RS not measure?: The JXBS-3001-PH-RS reports pH only — it does not report moisture, temperature, EC, N-P-K, salinity and TDS. On the same RS-485 bus, add moisture: JXBS-3001-TR (4-in-1); temperature: JXBS-3001-TR (4-in-1); EC: JXBS-3001-TR (4-in-1).
How many Modbus registers does the JXBS-3001-PH-RS expose?: This guide documents 4 registers, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include Low-precision pH, High-precision pH, Device address and Baud rate.

Alternatives

How this differs from similar models

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