Generic

Modbus RTU Sensor

60 minutesAdvancedModbus RTU

What You Need

USB-to-RS485 adapter

Shielded twisted pair cable (length varies)

120 ohm termination resistors (2x) (x2)

Flowstate CL260 edge nodeIncluded in kit

Customer provides:

1
Identify RS-485 terminals
Locate the RS-485 A (+), B (-), and GND terminals on the sensor. These are typically screw terminals labeled A/B or D+/D-.
2
Wire RS-485 bus
Connect shielded twisted pair cable from the sensor to a USB-to-RS485 adapter on the Flowstate edge node. Use daisy-chain topology for multiple sensors.
Add 120 ohm termination resistors at both ends of the bus. Maximum bus length: 1200m (4000ft).
3
Power the sensor
Provide power per the sensor's spec (commonly 12-24V DC). Use the same power supply ground as the RS-485 bus ground.

1
Set Modbus address
Set a unique Modbus station address (1-247) on the sensor via DIP switches, buttons, or configuration software. Note the baud rate and parity settings.
2
Configure register map
Obtain the sensor's Modbus register map from the manufacturer. Note register addresses, data types (INT16, FLOAT32), and byte order (big/little endian).
3
Create Flowstate template
In the Flowstate edge node, create a Modbus RTU device template with the sensor's register map. Map registers to named metrics.

1
Read test registers
Use modpoll or the Flowstate diagnostics tool to read a known register. Verify the value matches the sensor's display.
2
Dashboard check
Sensor metrics appear in Flowstate with correct units and scaling.

Configurable — depends on sensor register map

Typical: temperature, pressure, humidity, flow, level, vibration

Sensor status / fault register

Raw register values (INT16 / FLOAT32)

Don't have Modbus RTU access?

The universal CT clamp works on any machine — 15 minutes, zero configuration.

Calculate what downtime is costing you, then get started.