Watlow CLS216 Multi-Loop PID Temperature Controller
Watlow CLS216 | Multi-Loop PID Temperature Controller
The Watlow CLS216 is a high-density, multi-loop PID controller designed for sophisticated thermal management in industrial environments.
Part of the SERIES CLS200 family (formerly Anafaze), the CLS216 is the 16-loop powerhouse of the series, offering a complete control solution in a compact, panel-mount design.
It is engineered to replace multiple individual controllers, reducing hardware costs, panel space, and integration complexity.
Technical Parameter Table
| Feature | Specification |
| Control Loops | 16 Heat/Cool Loops (PID or On-Off) |
| Input Channels | 16 Single-ended Analog Inputs |
| Sensor Types | Thermocouples (J, K, T, R, S, B, E, N), RTDs (100Ω Platinum), 0-5VDC, 4-20mA |
| Digital Outputs | Up to 34 (with mass termination) |
| Digital Inputs | Up to 8 (recipe select, remote start/stop) |
| Accuracy | 0.1% of Span |
| Resolution | 14-bit A/D Converter (0.006%) |
| Communication | EIA/TIA-232 and 485 (Modbus® RTU or ANSI) |
| Power Supply | 15 to 24V DC @ 1A (max) |
| Sampling Rate | 1.5 samples per second per channel |
Unique Product Description
The CLS216 stands out due to its “Job Memory” and “Mass Termination” capabilities.
While many controllers require manual reconfiguration for different products,
the CLS216 can store and recall up to 8 complete process setups (jobs) instantly via the keypad or digital inputs.
This makes it the premier choice for “High-Mix, Low-Volume” manufacturing where rapid changeovers are critical to maintaining uptime.
Product Advantages and Features
Panel Efficiency: Consolidates 16 loops into a single cutout, drastically reducing “panel clutter.”
Advanced Autotune: Features a proprietary algorithm that tunes each loop independently, even in systems with high thermal lag.
Failure Detection: Built-in intelligence detects reversed, shorted, or open sensors, triggering alarms before damage occurs.
Firmware Options: Available with Standard, Ramp/Soak, or Enhanced (Cascade, Ratio, and Differential control) firmware.
Seamless PLC Integration: Optimized Modbus® RTU mapping allows it to act as an intelligent I/O subsystem for a master PLC.
Application Cases
Plastic Extrusion: Managing 16 separate heat zones on large-scale extrusion barrels and dies for uniform melt quality.
Thermoforming: Precise control of multi-zone infrared heater banks to ensure even sheet heating without sagging.
Semiconductor Ovens: Maintaining strict atmospheric and thermal ramp-up profiles in curing and aging ovens.
Packaging Machinery: Synchronizing multiple sealing bars and glue pots on high-speed vertical form-fill-seal (VFFS) lines.
Installation and Maintenance
CLS216
Installation
Mounting: Install the unit in a standard 1/4 DIN cutout. Use the provided mounting brackets to ensure a NEMA 4X (IP65) seal if required.
I/O Connection: For all 16 loops, use the 50-pin SCSI cable and TB50 terminal board. For smaller configurations, the 18-pin block may be used.
Noise Mitigation: Keep high-voltage AC lines separate from the low-voltage sensor inputs. Use shielded twisted-pair (STP) wiring for communication.
Maintenance
Terminal Verification: Check the SCSI cable connection every 6 months to ensure the locking tabs are secure.
Battery Backup: The internal memory is protected; however, periodically backing up configurations via the serial port using Watlow’s EZ-ZONE® Configurator is recommended.
Display Care: The vacuum fluorescent display (VFD) is high-visibility; keep the front bezel clean with a soft, dry cloth to prevent scratching.
Other Models in the Same Series
The SERIES CLS200 is designed to scale with your machine’s complexity:
Model Loops Best For
CLS204 4 Loops Small benchtop equipment and test stands
CLS208 8 Loops Mid-sized extrusion and packaging machines
CLS216 16 Loops Large industrial ovens and complex zones
Support Note: Legacy versions of the CLS216 may use different EPROM versions. Always verify the firmware version displayed on power-up when ordering replacement boards