What baud rate does the Renke RS-SD-N01-TR-1 use by default?

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

What supply voltage does the Renke RS-SD-N01-TR-1 need?

DC 4.5–30 V (RS-485 variant) (Low).

How do I change the Renke RS-SD-N01-TR-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 Renke RS-SD-N01-TR-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 Renke RS-SD-N01-TR-1 not measure?

The Renke RS-SD-N01-TR-1 reports moisture only — it does not report temperature, EC, pH, N-P-K, salinity and TDS. On the same RS-485 bus, add temperature: Renke RS-WS-N01-TR; EC: Renke RS-ECTHPH-N01-TR-1; pH: Renke RS-ECTHPH-N01-TR-1.

How many Modbus registers does the Renke RS-SD-N01-TR-1 expose?

This guide documents 1 register, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include Soil moisture content.

Home / Sensors / Renke RS-SD-N01-TR-1

Renke · RS-485 sensor

Shandong Renke Control Technology

Renke RS-SD-N01-TR-1

Renke single-parameter TDR soil-moisture probe (×100 scale, baud 9600).

✓ Verified for SankhyaMoistureVerification 0.90 · datasheet-confirmed

At a glance

The Renke RS-SD-N01-TR-1 is a single-parameter RS-485 soil probe reporting moisture over Modbus-RTU on RS-485 at 9600 bps, 8N1, on DC 4.5–30 V (RS-485 variant). This guide documents 1 register, default Modbus address 1. It does not report temperature, EC, pH and others. For those on the same bus: temperature → Renke RS-WS-N01-TR; EC → Renke RS-ECTHPH-N01-TR-1. Sankhya firmware profile: RENKE_SD_1in1.

Quick reference

Bus & electrical specs

Protocol

Modbus-RTU over RS-485

Default baud

9600 bps

Serial format

8N1

Function codes

0x03

Supply voltage

DC 4.5–30 V (RS-485 variant)

Power

Low

Default address

Ingress / housing

IP68

Probe / element

TDR frequency-domain, stainless

Operating temp.

−40 to +80 °C (probe)

Firmware profile

RENKE_SD_1in1

Specs sourced from: Official Renke RS-SD-N01-TR Type-485 manual. (Analog SKU variant is 3.3–5.5 V; the RS-485 unit is wide-voltage.)

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
0001H	40002	Soil moisture content	uint16	0.01	%	RO	CORRECTION v3: Scale is 0.01 (divide raw value by 100). Range 0-100%. Accuracy ±3% (0-53%), ±5% (53-100%).

Example poll

Worked query

# Read moisture (1 register at 0x0001) request 01 03 00 01 00 01 D5 CA response 01 03 02 0F 2D 7D A9 # 0F2DH=3885 => moisture=38.85%

Field notes

Notes & caveats

CORRECTIONS v3 from official Renke PDF: (1) Default baud 9600 not 4800. (2) Scale factor confirmed 0.01 — raw 3885 = 38.85%. (3) Register confirmed at 0001H. (4) Moisture only. (5) Config (address/baud) changed via hardware SET mode with shield wire — no Modbus write registers documented for this model. Probe 304 SS (not 316L).

FAQ

Common questions

What baud rate does the Renke RS-SD-N01-TR-1 use by default?: 9600 bps, 8N1. It is a Modbus-RTU slave; default address 1.
What supply voltage does the Renke RS-SD-N01-TR-1 need?: DC 4.5–30 V (RS-485 variant) (Low).
How do I change the Renke RS-SD-N01-TR-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 Renke RS-SD-N01-TR-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 Renke RS-SD-N01-TR-1 not measure?: The Renke RS-SD-N01-TR-1 reports moisture only — it does not report temperature, EC, pH, N-P-K, salinity and TDS. On the same RS-485 bus, add temperature: Renke RS-WS-N01-TR; EC: Renke RS-ECTHPH-N01-TR-1; pH: Renke RS-ECTHPH-N01-TR-1.
How many Modbus registers does the Renke RS-SD-N01-TR-1 expose?: This guide documents 1 register, read with function code 0x03 and written with 0x06 where the register is RW. Documented entries include Soil moisture content.

Alternatives

How this differs from similar models

How the Renke RS-SD-N01-TR-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
Renke RS-ECTHPH-N01-TR-1	Sibling	Moisture, Temperature, EC, pH, Salinity, TDS	4800	Adds temperature, EC, pH, salinity and TDS. Default baud 4800.
Renke RS-WS-N01-TR	Sibling	Moisture, Temperature	4800	Adds temperature. Default baud 4800.

Same family

Related Renke 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.