PLC sequence and machine states
Translate the agreed process into explicit states, transitions, permissives, alarms and recovery behavior. The final sequence should be reviewed against the machine's actual operating procedure.
Industrial Automation Products · Engineering Services · Quote Support
Utilities
AHU Automation
AHU automation coordinates fans and available air-side measurements and equipment signals based on the building or process requirements. Automation scope depends on the equipment, operating sequence, existing controls and process requirements. Share the machine details and desired outcome to define a suitable control approach.
Application overview
AHU automation coordinates fans and available air-side measurements and equipment signals based on the building or process requirements.
Typical requirements to define
- Fan and damper arrangement
- Temperature, pressure or air-quality measurements required
- Operating schedule and occupied modes
- Filter, freeze and equipment alarm inputs where installed
Example process sequence
- Check schedule, demand and equipment permissives
- Enable the configured fans and associated devices
- Monitor required measurements and equipment feedback
- Apply agreed setpoint or mode changes
- Stop and alarm according to the equipment sequence
Machine states and operating sequence
Document the machine cycle, operator actions, required permissives, abnormal conditions and safe recovery path before mapping them to controller logic.
Operator interface and alarms
An HMI may show mode, step, status, setpoints and actionable alarm information. Screen behavior and operator permissions should match the plant's procedures.
Safety and fault handling
Safety functions must be designed for the risk assessment and applicable machine requirements. Standard PLC logic should not be treated as a substitute for safety-rated hardware or a validated safety design.
Air-side process signals
Sensor types, locations, control ranges and sequence depend on the AHU design and the ventilation requirements supplied for the project.
Related automation technologies
Explore the control systems that may be relevant to this scope.
Products from the catalog
These active catalog products are related by their existing category. Confirm model compatibility and availability for your application.
PLC
Siemens S7-1200 CPU 1214C DC/DC/DC PLC – 14DI/10DO/2AI, 6ES7214-1AG40-0XB0
Siemens S7-1200 CPU 1214C DC/DC/DC PLC with 14 digital inputs, 10 digital transistor outputs and 2 analog inputs. 24 V DC supply, 150 KB program/data memory and PROFINET communication.
Industrial Communication
RS232 PLC HMI Communication Cable – DB9 Serial Programming Cable for Industrial Automation
RS232 serial communication cable for compatible PLCs and HMIs, suitable for programming, configuration, commissioning, diagnostics and industrial automation communication.
VFD & Drives
Delta VFD EL SERIES 0.025 TO 5 HP | 0.2KW TO 3.7KW
Delta VFD002EL21A 0.2kW (0.25HP) VFD with 200–240V single-phase input, 3-phase output, 1.6A rated output current, V/F control, RS-485 Modbus, built-in braking transistor and 0.1–600Hz frequency range.
HMI
Delta DOP-107CV 7 Inch Touchscreen HMI – 800×480 TFT, RS-232/RS-485/RS-422, USB
Delta DOP-107CV 7-inch industrial touchscreen HMI with 800×480 resolution, 65,536-color TFT display, 256 MB RAM/ROM, RS-232/RS-485/RS-422 communication, USB Host/Client, and 24 VDC power supply.
PLC
Delta DVP28SV11T2 PLC – DVP-SV2 Series, 16 Digital Inputs, 12 Transistor Outputs, 24V DC
Delta DVP28SV11T2 DVP-SV2 Series high-performance slim PLC with 16 digital inputs and 12 NPN transistor outputs. Featuring high-speed processing, high-speed counters and pulse outputs, it is suitable for machine automation, motion control, packaging, printing, conveyor and industrial control applications
PLC
Delta DVP12SA2 PLC – DVP-SA2 Advanced Slim PLC, 8DI/4DO, 24VDC, RS-232/RS-485
Delta DVP12SA2 DVP-SA2 Advanced Slim PLC with 8 digital inputs, 4 digital outputs, 24VDC supply, 16K steps and RS-232/RS-485 Modbus communication.
PLC
Delta DVP60ES200R PLC – DVP-ES2, 36DI/24 Relay Output, 16K Steps
Delta DVP60ES200R DVP-ES2 PLC with 36 digital inputs, 24 relay outputs, 100–240VAC power supply and 16K-step program capacity for industrial automation.
PLC
Delta DTC1000 Temperature Controller – 24VDC, PID/ON-OFF Control, RS-485 Modbus
Delta DTC1000 modular temperature controller with 24VDC supply, PID/ON-OFF control, multiple sensor inputs and RS-485 Modbus communication.
Related engineering services
PLC programming
Discuss the equipment, existing controls and project requirements with our engineering team.
Request service quote →HMI programming
Discuss the equipment, existing controls and project requirements with our engineering team.
Request service quote →Machine automation
Discuss the equipment, existing controls and project requirements with our engineering team.
Request service quote →Related applications and topics
Frequently asked questions
What information is useful for a ahu automation enquiry?
Describe the machine or process, current controls, operating sequence, required modes, available drawings and the changes you want to make. Include known controller and drive models where possible.
Can existing equipment be considered?
Yes. Include the installed controller, HMI, drives, sensors and any drawings or fault details so the existing arrangement can be reviewed before defining scope.
Discuss your automation requirements
Share the equipment details, current controls and process sequence for a scope review.