Watlow CLS216 Multi-Loop PID Temperature Controller
Watlow CLS208 | 8-Loop Multi-Zone PID Controller
The Watlow CLS208 is a compact, high-performance multi-loop controller designed to manage up to eight independent thermal loops.
As a core member of the SERIES CLS200 (formerly Anafaze), the CLS208 strikes the perfect balance between the entry-level 4-loop units and the high-density 16-loop systems.
It provides a centralized interface for monitoring and controlling temperature, pressure, or flow, making it a favorite for mid-sized industrial machinery.
Technical Parameter Table
| Feature | Specification |
| Control Loops | 8 Independent Heat/Cool Loops |
| Input Type | Universal (Thermocouples J, K, T, S, R, B; RTD; 0-5VDC; 4-20mA) |
| Output Type | Distributed I/O (SSR, Relay, or Analog via DAC) |
| Display | High-visibility Vacuum Fluorescent (VFD) |
| Communication | Serial RS-232 / RS-485 (Modbus® RTU / ANSI) |
| Accuracy | ±0.1% of Full Scale |
| A/D Resolution | 14-bit |
| Power Requirements | 12 to 24V DC |
| Memory | Non-volatile (Battery backup for Job storage) |
Unique Product Description
The Watlow CLS208 is defined by its “Zone Grouping” logic. Unlike standard controllers that treat every loop as a silo,
the CLS208 allows users to group loops together for synchronized startups or shared alarm behaviors.
This is particularly useful in applications where one zone’s temperature is dependent on another (cascade or ratio control),
providing a level of “process awareness” that prevents equipment damage during uneven heating cycles.
Product Advantages and Features
Space Saving: Replaces eight 1/16 DIN controllers with a single 1/4 DIN unit, reducing panel wiring by up to 60%.
Job Recipes: Stores up to 8 different process “Jobs,” allowing operators to switch between different production materials with a single button press.
Smart Alarms: Includes global alarms, individual loop alarms, and “Deviation Alarms” that track how far a zone has drifted from the setpoint.
Flexible Firing: Supports various output types, including time-proportioning for SSRs or linear DC for valves.
Rugged Front Panel: Rated NEMA 4X (IP65) for resistance to dust and water washdowns.
Application Cases
Plastic Injection Molding: Precise control of the manifold and nozzle temperatures to ensure consistent part quality.
Food Processing: Managing multiple heating zones in commercial industrial ovens or conveyor fryers.
Packaging Lines: Controlling the temperature of multiple heat-sealing bars on horizontal flow wrappers.
Laboratory Test Chambers: Coordinating heating and cooling loops for environmental stress screening (ESS).
Installation and Maintenance
Installation
Cutout: Standard 1/4 DIN panel cutout ($92mm \times 92mm$).
Wiring: Use the 34-pin mass termination connector for I/O to save time. Ensure that high-voltage power lines are routed away from low-voltage thermocouple wires to avoid signal interference.
Grounding: Always connect the chassis ground terminal to a low-impedance earth ground to ensure 14-bit measurement stability.
Maintenance
VFD Longevity: To extend the life of the display, utilize the “Display Dim” or sleep mode feature if the unit is not being monitored constantly.
Calibration: It is recommended to verify the calibration of each of the 8 loops every 12 months using a certified thermocouple calibrator.
Back-up: Use the Watlow AnaWin software to backup your 8 Job Recipes to a PC for easy recovery in case of hardware replacement.
Other Models in the Same Series
The SERIES CLS200 allows for easy scaling based on your zone requirements:
Model Loop Capacity Best Use Case
CLS204 4 Loops Small heaters, lab stirrers, and hot plates.
CLS208 8 Loops Mid-sized extrusion lines and packaging.
CLS216 16 Loops Large-scale furnaces and complex chemical reactors.
Related Models & Accessories
TB50: 50-pin terminal board for easy wiring.
DAC-08: Digital-to-Analog converter for 4-20mA output requirements.
Serial Converters: RS-232 to RS-485 adapters for long-distance communication (up to 4.000 feet).