AirMASTER FORM Controller — Overview & Navigation – South-Tek Systems

Applies to: STS Series (5–30HP) · STSH Series · STSD · STSP · STSP2 — all South-Tek screw compressor models use the AirMASTER FORM controller (UL certified).

Overview

The AirMASTER FORM is a microprocessor-based compressor controller manufactured by CMC (Compressor and Machine Controls). It manages all compressor operating states, provides real-time parameter monitoring, displays faults and maintenance reminders, and supports optional networking and remote monitoring via RS485 Modbus, IoT (Ethernet/TCP-IP), or fieldbus modules.

Hardware

Keypad

Button	Function
▲ (Up arrow)	Scroll up / increase value
▼ (Down arrow)	Scroll down / decrease value
START (green)	Start the compressor
STOP (red)	Stop the compressor (normal unloaded stop)
ESCAPE	Exit menu / reset faults (hold to reset)

Graphic Display

The FORM uses a graphical LCD display showing real-time operating data including compressor state, air pressure (inside and outside separator), air/oil temperature, running hours, maintenance countdowns, and active fault or warning codes. Status bar icons indicate the active operating mode.

User Account Levels

The FORM supports multiple access levels. Operators can view operating data and acknowledge alarms. Service and configuration parameters require a PIN or authorized service account. Contact South-Tek if service-level access is needed.

Menu Structure

Menu	Contents
P01 — Status	Real-time operating values: pressure, temperature, load status, running hours
P02 — Inputs/Outputs	Digital and analog I/O status
P03 — Alarms	Active and historical alarm log
P04 — Maintenance	Maintenance countdown timers per component
P05 — Controller Info	Serial number, software version, software ID
P06 — Network / IoT	IoT module settings, MAC address, IP configuration
P08 — Data Graph	Trend graph for pressure and temperature (up to one month of data)
P10 — Configuration	Compressor-specific setup parameters (service access required)
P11 — Motor Control	Star-delta and VSD motor parameters
P12 — Protection	Temperature and overheating protection thresholds
P15 — Pressure Control	Load/unload pressure setpoints and schedule
P20 — Inverter	VSD-specific parameters (VSD models only)
P27 — IP Settings	Ethernet IP address configuration for IoT module

Operating States

State	Description
Ready	Compressor energized, no active faults, awaiting start command
Starting	Motor starting sequence in progress (star-delta transition or VSD ramp)
Load	Compressor running, suction valve open, producing compressed air
Unload	Suction valve closed; compressor running unloaded; idle timer counting
Auto-stop	Idle timer expired; compressor stopped; will auto-restart when pressure drops to lower setpoint
Fault	Compressor stopped due to protective alarm; fault code displayed
Emergency Stop	E-stop button pressed; compressor locked out pending reset

Control Modes

Local Control

The compressor is started and stopped using the START and STOP buttons on the controller panel. This is the default mode.

Remote / Automatic Control

When configured for remote operation, the compressor can be started and stopped via digital input signals (remote start/stop), Modbus RS485 commands, or IoT remote messages. The automatic restart parameter (disabled by default) allows the compressor to restart automatically after a power interruption.

⚠ Warning — Automatic Restart If automatic restart is enabled, the compressor will restart without operator input after power is restored. This parameter must be confirmed before any maintenance. It is disabled in factory default settings.

Maintenance Warnings

The AirMASTER FORM displays maintenance reminders when a component reaches its service interval. The compressor continues running while maintenance warnings are active — the warnings remain on screen until manually reset.

▲ Attention Do not reset a maintenance warning until the corresponding maintenance has been physically performed. Resetting without completing service is a warranty violation and the manufacturer cannot be held liable for resulting damage.

Optional Modules

Module	Function
RS485 / Modbus RTU	Fieldbus communication (Airbus485 proprietary or Modbus RTU slave/master). Enables integration with building management systems and SCADA.
IoT (Ethernet / TCP-IP)	Web browser monitoring over Ethernet. Provides Health, Performance, Custom, and Events dashboard pages. Supports remote start/stop flagging. Automatically syncs controller timestamp if internet-connected.
IO Extension	Additional analog and digital I/O for expanded sensor inputs (inlet vacuum, oil temperature, delivery temperature, oil pressure, oil filter differential, cooler approach temperatures).
Fieldbus Network Cards	Optional cards for Profibus, DeviceNet, EtherNet/IP, and other industrial protocols.

ℹ Note The complete AirMASTER FORM Configuration Manual (V3) is included as Addition Chapter 1 of your compressor documentation package. It covers the full parameter list, menu map, message codes, symbol definitions, and IoT module setup in detail.

For controller support or configuration assistance, contact South-Tek Systems: (910) 415-1880 or support@southteksystems911.zendesk.com