Modular chillers are widely used in commercial buildings, industrial facilities, and data centers where reliable cooling performance and centralized monitoring are required. As the core control unit of a chiller system, the chiller control cabinets manages the operation of compressors, fans, pumps, and protection functions while continuously collecting operating data such as temperature, pressure, flow, and equipment status.

With the increasing demand for digital monitoring and energy management, chiller systems are often integrated with SCADA or Building Management Systems (BMS). This requires the control panel to support various types of field signal acquisition and provide a reliable communication interface between field devices and upper-level monitoring platforms.

The BL190 IO Acquisition Module can be integrated inside the chiller control cabinets as an additional data acquisition unit, enabling the collection of multiple industrial signals and transmitting the collected data to SCADA systems through Modbus TCP communication.

1. Typical Signal Types in Chiller Control Cabinets

A modular chiller control panel usually contains controllers, electrical protection components, communication interfaces, and field signal acquisition units. The main signal types include:

1.1 Temperature Measurement Signals

Temperature monitoring is essential for stable chiller operation. Typical measurement points include:

• Chilled water supply temperature
• Chilled water return temperature
• Condenser water supply and return temperature
• Evaporator temperature
• Condenser temperature
• Compressor discharge temperature
• Ambient temperature

Common sensor types:

• RTD (PT100/PT1000)
• Thermocouple (TC)
• Analog temperature transmitters (4-20mA)

The BL190 supports RTD, TC, and analog input channels, allowing direct connection with various temperature sensing devices used inside chiller systems.

1.2 Pressure and Analog Measurement Signals

During operation, chillers need continuous monitoring of pressure and other analog parameters, including:

• Suction pressure
• Discharge pressure
• Refrigerant pressure
• Water pressure
• Flow transmitter signals
• Valve position feedback

Common signal formats:

• 4-20mA
• 0-10V

With analog input channels, the BL190 can acquire signals from pressure transmitters, flow meters, and valve feedback devices for centralized monitoring.

1.3 Digital Status Signals

The control panel also collects various equipment status and protection signals, such as:

• Compressor running status
• Fan running feedback
• Pump operation status
• High/low pressure protection
• Water flow switch status
• Anti-freezing protection
• Alarm signals

These signals are typically transmitted through:

• Digital Input (DI)
• Dry contact signals

The BL190 digital input channels can be used to collect equipment status and alarm information for real-time condition monitoring.

1.4 Control Output Signals

Some field devices require control signals from the chiller panel, including:

• Pump start/stop control
• Fan control
• Solenoid valve control
• Alarm output
• Interlock control

Common signal types:

• Digital Output (DO)
• Analog Output (AO)

The BL190 supports digital output and analog output channels for flexible control signal transmission.

1.5 RS485 Modbus RTU Device Integration

Modern chiller control panels often integrate intelligent devices such as:

• Energy meters
• Variable frequency drives (VFD)
• Pump controllers
• Flow meters
• Smart temperature controllers
• Pressure monitoring devices

These devices commonly use:

• RS485
• Modbus RTU

The BL190 can collect data from Modbus RTU devices and integrate multiple field instruments into a unified monitoring system.

2. BL190 Integration Architecture

The BL190 can be installed inside the Chiller Control Panel and serve as a bridge between field devices and SCADA platforms.

Typical architecture:

The BL190 collects different industrial signals from the chiller system, converts field data into standardized communication data, and uploads information to SCADA through Modbus TCP.

3. BL190 Supported Signal Types

In modular chiller control panels, the BL190 IO Acquisition Module provides a flexible method for expanding field data acquisition capabilities.

By supporting multiple industrial signal types, including DI, DO, AI, AO, RTD, TC, and RS485 Modbus RTU, the BL190 enables different sensors and intelligent devices to be connected within the control cabinet.

Through Modbus TCP communication, collected data can be transferred to SCADA platforms for equipment monitoring, operational analysis, and system integration.

A modular chiller control panel requires the integration of various signals from temperature sensors, pressure transmitters, intelligent meters, and equipment status points. The BL190 IO Acquisition Module can be installed inside the control panel as a compact data acquisition solution, collecting multi-type industrial signals and transmitting data to SCADA systems through Modbus TCP, supporting digital monitoring and intelligent operation of chiller systems.