New APX1-C2 Online pH ORP Controller Supports RS485 Modbus RTU and JSON Data Output

For plant engineers building connected water treatment systems, data accessibility is everything. The APX1-C2 online pH/ORP controller from Daruifuno answers this need with an RS485 interface that supports both standard Modbus RTU protocol and JSON text format, letting integrators choose the data model that best fits their architecture.

Two Protocols, One Interface

When Modbus is selected, the instrument acts as a standard slave on the network. The host can read measurement results using function code 04, with temperature, pH, and ORP values mapped to clearly defined register addresses:

When JSON is selected, the controller automatically broadcasts the measured values as readable text every minute — ideal for lightweight dashboards, loggers, and cloud gateways that prefer structured text over register polling.

Complementary Analog Outputs

Alongside its digital interface, the APX1-C2 provides two active 4–20 mA or 0–20 mA outputs with a maximum load of 1000 Ω. Each channel can be assigned to the main value or temperature, so legacy analog control loops and modern digital systems can coexist without compromise.

Why It Matters

Flexible connectivity means faster commissioning, easier retrofits, and a shorter path from sensor to decision. Whether you are upgrading an existing plant or designing a new SCADA-controlled process, the APX1-C2 delivers the measurement accuracy and communication options your project requires.

Designed for Integration Projects

System integrators value predictable, well-documented interfaces. The APX1-C2 ships with a complete register map and clear protocol documentation, reducing commissioning time and eliminating guesswork. Because the same hardware can speak either Modbus RTU or JSON, projects can standardize on a single controller model across mixed control environments.

Key Benefits

• Standard Modbus RTU slave with function code 04 read support
• Automatic JSON broadcast of live values every minute
• Two active 4–20 mA outputs for analog loops
• RS485 daisy-chain wiring for multi-drop networks
• IP66 panel-mount housing for industrial environments

From Sensor to Decision

Reliable pH and ORP measurement is the foundation of effective process control. By making that data easy to read, transmit, and act upon, the APX1-C2 helps plants reduce chemical consumption, avoid compliance penalties, and keep treatment processes within their target windows.

Contact Daruifuno for a Modbus register map, integration guidance, or a sample unit for evaluation.