Electrical cabinets, control cabinets, UPS cabinets, telecom cabinets, distribution boxes and equipment enclosures are common in industrial and commercial projects. These cabinets often contain power components, terminals, cables, control modules and communication devices. Once abnormal smoke or overheating starts inside the cabinet, the problem may not be noticed immediately from outside.
For many projects, a simple local smoke detector is not enough. Customers often need the alarm signal to be connected to a monitoring system, alarm input module, local control panel, PLC, BMS or other host system. This is why cabinet alarm linkage is important.
A cabinet-level detector should not only detect visible smoke. It should also help users monitor the cabinet environment and provide output signals for system integration. ANWETECH AT-S232 is designed for this type of application. It combines smoke detection, temperature measurement and humidity measurement in one compact detector, while supporting both RS485 communication and relay normally open / normally closed output.
ANWETECH AT-S232 is a photoelectric smoke, temperature and humidity detector. It is a 3-in-1 sensor designed to monitor smoke, ambient temperature and humidity conditions in cabinets, enclosures and small protected spaces.
The smoke detection section uses a labyrinth chamber and photoelectric signal processing technology. This design helps the detector monitor visible smoke while resisting common interference factors such as dust, insects and external white-light influence.
The detector responds to visible smoke generated by slow smouldering fires or open flames. When the ambient smoke concentration reaches the configured alarm threshold, the detector generates audible and visual alarm indication. When the smoke concentration drops below the alarm threshold, the detector returns to normal monitoring status.
For cabinet alarm linkage, the most important feature of AT-S232 is that it provides RS485 communication and relay NO / NC output. This allows the detector to support both data integration and alarm contact linkage.
Cabinet protection should not only focus on smoke. In real project environments, different parameters can provide different types of warning information.
Smoke detection helps identify visible smoke from smouldering materials, cable insulation damage or early fire development. Temperature monitoring helps users observe whether the cabinet environment is becoming hotter than normal. Humidity monitoring helps users understand the environmental condition inside or around the cabinet, especially where moisture, condensation or unstable humidity may affect electrical equipment.
By combining these three monitoring functions in one detector, AT-S232 provides a more practical cabinet-level monitoring solution. This is useful for electrical contractors, system integrators, BMS contractors, fire protection contractors and cabinet manufacturers who need a compact device for both fire early warning and environmental monitoring.
AT-S232 supports relay normally open and normally closed output. This is a key difference between AT-S232 and AT-S233.
The relay output allows the detector to provide a switching signal for project alarm linkage. In practical engineering applications, this type of output may be used to connect with alarm input modules, local alarm panels, monitoring interface modules, IO modules or other approved alarm receiving equipment according to the final project design.
The relay wiring of AT-S232 includes a common terminal, normally open terminal and normally closed terminal. This gives the project designer flexibility when selecting the alarm input logic required by the receiving system.
For projects where the customer needs a simple alarm contact in addition to RS485 communication, AT-S232 is the recommended model. It is especially useful when the cabinet detector needs to send both a communication signal and a local alarm contact signal.
In addition to relay output, AT-S232 also supports RS485 communication with Modbus-RTU protocol. This makes it suitable for projects where temperature and humidity data need to be transmitted to a host system for monitoring, integration or secondary development.
The standard communication parameters include 9600 bps baud rate, 8 data bits, no parity and 1 stop bit. The default station address is 0x01, and the broadcast station address is 0xFE.
RS485 Modbus communication is valuable for centralized monitoring systems. It allows cabinet monitoring data to be connected to a user host system, PLC, BMS or other monitoring platform. This is especially important when multiple cabinets are installed in one electrical room, equipment room, telecom site, industrial facility or energy storage project.
AT-S232 also provides local alarm indication. In normal monitoring status, the red LED flashes once every 8 seconds. During smoke alarm, fault or alarm status, the red LED stays on. The built-in buzzer provides continuous alarm sound during smoke alarm or test status.
This local indication is helpful for site maintenance personnel. When they are near the cabinet, they can quickly identify the alarm status through the LED and buzzer. At the same time, the RS485 communication and relay output can send alarm or monitoring information to the system level.
This combination of local indication and external signal output makes AT-S232 suitable for cabinet applications where both on-site alarm visibility and remote system integration are required.
ANWETECH AT-S232 and AT-S233 are both 3-in-1 smoke, temperature and humidity detectors. The main difference is the output method.
AT-S232 supports RS485 communication and relay normally open / normally closed output. It is suitable for cabinet alarm linkage applications where the project requires both communication data and relay contact output.
AT-S233 supports RS485 output only. It is suitable for projects where the detector only needs to transmit data through RS485 Modbus-RTU to the host system, without relay output.
For alarm linkage projects, AT-S232 is the better selection because it provides relay NO / NC output. For monitoring-only projects where the host system reads data through RS485, AT-S233 may be sufficient.
AT-S232 can be used in many cabinet and small-space monitoring applications.
In electrical cabinets, it can monitor visible smoke, temperature and humidity and provide alarm output when abnormal smoke reaches the alarm threshold. In control cabinets, it can support integration with PLC or automation monitoring systems. In UPS cabinets and telecom cabinets, it can provide cabinet-level fire early warning and environmental condition monitoring.
For box-type substations and distribution cabinets, AT-S232 provides a compact solution for small protected spaces where traditional room-level detection may not be enough. For energy storage environments and battery-related cabinets, the detector can support visible smoke monitoring and environmental monitoring according to the final project design.
The product should always be selected and installed according to project drawings, confirmed product documentation and local code requirements.
AT-S232 uses separate wiring for power, RS485 communication and relay output.
For RS485 sensor wiring, the red wire is DC12–24V positive, the black wire is negative, the yellow wire is 485A and the blue wire is 485B.
For relay wiring, the white wire is the common terminal, the green wire is the normally open terminal and the brown wire is the normally closed terminal.
Before project wiring, the final wiring definition should be confirmed with the product label, project drawings and approved technical documentation. For relay linkage, the receiving equipment input type and circuit design should also be confirmed by the project engineer.
Correct installation is important for stable detector performance.
The detector is suitable for ceiling-mounted installation in cabinets, enclosures and small protected spaces. It should preferably be installed horizontally. If inclined installation is necessary, the tilt angle should not be greater than 45 degrees.
There should be no obstruction within 0.5 m around the detector. The horizontal distance from the detector to the air-conditioning supply outlet should not be less than 1.5 m. These installation requirements help reduce obstruction and airflow influence around the detector.
The detector includes a test button. Short-pressing the test button can test the audible and visual alarm function. It is recommended to perform a simulated fire alarm test every six months to verify that the detector works properly.
AT-S232 is suitable for cabinet alarm linkage because it combines four important functions in one compact device.
First, it provides photoelectric smoke detection for visible smoke monitoring. Second, it provides temperature and humidity measurement for cabinet environmental monitoring. Third, it supports RS485 Modbus-RTU communication for host system integration. Fourth, it provides relay normally open / normally closed output for alarm contact linkage.
This makes AT-S232 a practical choice for projects where the customer wants both data communication and direct alarm linkage from a cabinet-level detector.
