WATLOW MLS300-PM Processor Module (Central CPU),Discontinued

Watlow Anafaze MLS300-PM is the core Processor Module (PM) and central “brain” of the MLS300 modular multi-loop control system.

As a central CPU, it handles the logic, PID calculations, and system coordination for high-density thermal processes.

1. Introduction

The MLS300-PM Processor Module is the executive unit of the MLS300 system.

It is designed to work in a “stack” with expansion modules, primarily the AIM (Analog Input Module) and CIM (Control Interface Module).

While it does not directly house the sensor inputs (which reside in the AIM), the PM processes all incoming data and executes complex control strategies for up to 16 or 32 loops.

Though currently discontinued, it remains a vital component in legacy industrial automation and semiconductor manufacturing tools.

2. Technical Parameter Table

3. Product Advantages and Features

High-Density Logic: Consolidates the processing power of dozens of individual controllers into a single module, reducing cabinet complexity.

Versatile Control Modes: Supports advanced process features like Ramp/Soak, Cascade control, and Ratio control, which are often required in chemical or semiconductor processing.

On-Board Diagnostics: Provides real-time feedback on system health, including “System Safe” relays and CPU watchdog timers to prevent process runaway.

Job/Recipe Storage: Allows for multiple process configurations (Jobs) to be stored in non-volatile memory and recalled instantly.

4. Application Cases

Semiconductor Fabrication: Controlling complex multi-zone bake stations and CVD (Chemical Vapor Deposition) processes.

Multi-Zone Extrusion: Coordinating the thermal profile of long-barrel plastic extruders to ensure material consistency.

Environmental Stress Chambers: Managing the synchronization of temperature, humidity, and airflow loops.

Industrial Kilns/Ovens: Precise ramp-to-setpoint control for ceramic firing or composite curing.

5. Other Models in the Same Series

Since the MLS300 is a modular system, the PM is typically paired with:

MLS300-AIM: Analog Input Module (the physical interface for thermocouples/RTDs).

MLS300-CIM: Communication Interface Module (enables Modbus RTU/Serial comms).

MLS300-OIT: Remote Operator Interface Terminal (for external monitoring).

TB50 / TB18: Terminal Boards for physical wiring of high-density I/O.

MLS300-PM

6. Installation and Maintenance

Installation

Mounting: Ensure the unit is installed in a clean, ventilated 1/8 DIN cutout. If stacking modules, ensure ribbon cables are seated firmly.

Power: Use a regulated DC power supply. Since the PM controls the system timing, power fluctuations can cause “Watchdog” resets.

Grounding: Connect the chassis ground to a dedicated low-impedance industrial earth to prevent VFD display noise.

Maintenance

Memory Battery: The internal lithium battery retains the “Job” configurations. If the “Low Battery” alarm appears on the display, replace it immediately to avoid losing logic settings.

EPROM Updates: Ensure the EPROM chip version is consistent across all modules in the stack to prevent communication “Time-Out” errors.

Display Care: The VFD can dim over decades of use; use the “Screen Saver” or “Dim” settings in the setup menu to extend its lifespan.

7. Unique Product Description

“The Watlow MLS300-PM is the master architect of high-density thermal control.

By serving as the central intelligence for up to 32 loops, it transforms massive amounts of raw sensor data into surgical PID precision.

It is the definitive legacy CPU for systems where downtime is not an option and thermal uniformity is the only metric that matters.”