Yamatake MAH20-PC2100 Processor Module for Building Automation
Product Overview
The Yamatake (now Azbil) MAH20-PC2100 is a processor module within the MAH20 series of building automation controllers. Designed for HVAC and industrial environmental control systems, this module serves as the central processing unit, executing PID control loops, managing I/O, and handling communication with supervisory systems. The MAH20 series is widely used in cleanrooms, pharmaceutical facilities, and large commercial buildings where precise temperature, humidity, and pressure control is required.
Key Specifications
Model: MAH20-PC2100
Series: Yamatake MAH20 (Azbil)
Type: Processor module / CPU
Power Supply: 24 VDC (via backplane)
Program Memory: Flash ROM (non-volatile)
Control Loops: Up to 32 PID loops
Communication Ports: RS-485 (Modbus RTU, Yamatake protocol), optional Ethernet
Expansion: Up to 8 I/O modules (analog/digital)
Operating Temperature: 0°C to 50°C
Mounting: DIN rail or panel mount (within MAH20 rack)
Centralized Control for HVAC Systems
The MAH20-PC2100 is optimized for environmental control. It executes autotuning PID algorithms to maintain setpoints with minimal overshoot. The module can store up to 32 different control programs, allowing scheduled changes for day/night or seasonal operation. It also includes built-in alarm handling for sensor failure, valve stuck, or out-of-range conditions.
Flexible I/O Expansion
Via the MAH20 backplane, the processor module communicates with a range of I/O modules: analog inputs (4-20mA, 0-10V, RTD, thermocouple), analog outputs (0-10V, 4-20mA), digital inputs (dry contact, 24VDC), and relay outputs (2A 250VAC/30VDC). This modularity allows system designers to match the I/O count and type to the specific building zone.
Communication and Integration
The built-in RS-485 port supports Modbus RTU, enabling connection to building management systems (BMS), SCADA, or PLCs. The module can act as a Modbus slave, exposing process variables (temperature, pressure, valve position) to the central system. Optionally, an Ethernet adapter can be added for BACnet/IP or Modbus TCP connectivity.
Applications
Pharmaceutical cleanroom pressurization control
Data center cooling and humidity management
Hospital operating room HVAC
Museum and archive climate control
Industrial drying ovens and curing chambers
Programming and Configuration
The MAH20-PC2100 is configured using Yamatake’s “MAH20 Tool” software (Windows-based). Engineers can define PID parameters, setpoint schedules, alarms, and logic interlock conditions. The software supports online monitoring of process variables and trending of historical data. Parameter sets can be stored to a PC and downloaded to multiple controllers for standardization.
Conclusion
The Yamatake MAH20-PC2100 processor module offers a robust, field-proven solution for precision environmental control. Its flexible I/O, PID autotuning, and Modbus integration make it a reliable choice for demanding building and industrial automation applications.





