REX-C700 Digital PID Temperature Controller User Manual

1. Introduction

The CERTEON REX-C700 is a high-precision digital PID temperature controller designed for industrial applications requiring stable and accurate temperature management. It features a dual-color digital tube display, intelligent stability, and over-temperature protection. This manual provides essential information for the safe and effective installation, operation, and maintenance of your REX-C700 controller.

Figure 1: REX-C700 Digital PID Temperature Controller Overview

2. Safety Information

• Always disconnect power before installation or maintenance to prevent electric shock.
• Ensure proper grounding to avoid electrical hazards.
• Do not operate the device in environments exceeding specified temperature and humidity ranges, or where corrosive gases or strong electromagnetic radiation are present.
• Only qualified personnel should perform installation and wiring.
• Verify all connections are secure before applying power.

3. Product Overview

3.1. Panel Analysis

The REX-C700 features a clear dual-color digital tube display and intuitive control buttons for easy operation and monitoring.

Figure 2: Front Panel Layout and Indicators

• PV (Measured Value / Mode Display Value): Displays the current process value or parameter codes during setup.
• SV (Set Value / Mode Content Display): Displays the target set value or parameter settings.
• ALM1 Indicator: Illuminates when Alarm 1 is active.
• OUT1 Indicator: Illuminates when Output 1 is active.
• ALM2 Indicator: Illuminates when Alarm 2 is active.
• AT (PID Auto-tuning Indicator): Illuminates during the auto-tuning process.
• SET/Mode Key: Used to enter setup modes and confirm settings.
• Shift Key (<): Used to move the cursor during parameter adjustment.
• Decrease Key (v): Used to decrease numerical values or navigate options.
• Increase Key (^): Used to increase numerical values or navigate options.

3.2. Key Features

• High Control Precision: Utilizes PID fuzzy control for accurate temperature regulation.
• Compact Structure: Designed for efficient space utilization.
• Anti-interference: Industrial-grade design with surge, radiation, electrostatic discharge, and lightning protection.
• Long Service Life: Enhanced by a stable power supply with a copper transformer.
• Automatic Protection Function: Built-in mechanisms for reliable operation.
• Multiple Input Methods: Supports K, E, J, S, PT100, CU50 sensor types.
• Output Options: Available with Relay or SSR (Solid State Relay) outputs.

Figure 3: Internal Components and Terminal Quality

4. Specifications

Note: Some specifications may vary based on specific model configurations. Contact support for detailed information on custom requirements.

5. Installation

5.1. Mounting

The REX-C700 is designed for panel mounting. Ensure the panel cutout dimensions are accurate for a secure fit.

• Panel Size: 72x72mm
• Mounting Cutout: 68x68mm
• Embedded Depth: 100mm

Figure 4: REX-C700 Dimensions and Terminal Layout

5.2. Wiring

Refer to the wiring diagram provided on the side of the unit and in Figure 4. Ensure all connections are made correctly and securely. Incorrect wiring can damage the unit or lead to unsafe operation.

• Power Supply: Connect to terminals 1 and 2 (220V AC) or appropriate DC terminals if using a 24VDC model.
• Input Sensor: Connect your temperature sensor (K-type, PT100, etc.) to the designated input terminals (e.g., 9, 10, 11 for K-type). The controller supports multiple input types as shown in Figure 5.
• Output: Connect your control device (e.g., SSR, relay) to the output terminals (e.g., 4 and 5 for SSR output).
• Alarm Outputs: Connect alarm devices to the alarm output terminals (e.g., 6 and 7 for ALM1, 8 and 9 for ALM2).

Figure 5: Supported Input Sensor Types

Important: This controller does not measure temperature directly; it requires an external sensor (thermocouple or RTD) appropriate for your application. The universal input version supports up to 1200°C, while the default K-type input supports up to 999°C.

6. Operation

6.1. Basic Operation

1. Power On: After ensuring all wiring is correct, apply power to the controller. The display will light up, showing the current measured value (PV) and the set value (SV).
2. Setting the Target Temperature (SV):
   • Press the SET key once to enter the set value adjustment mode. The SV display will flash.
   • Use the ^ (Increase) and v (Decrease) keys to adjust the target temperature.
   • Use the < (Shift) key to move the cursor for faster adjustment of individual digits.
   • Press the SET key again to confirm the new set value and exit the adjustment mode.

6.2. PID Auto-tuning

The auto-tuning function helps the controller automatically calculate optimal PID parameters for your specific heating system, ensuring stable and precise temperature control.

1. Ensure the system is at a stable temperature or at room temperature.
2. Press and hold the SET key for a few seconds until the parameter menu appears.
3. Navigate through the parameters using the SET key until you find the auto-tuning parameter (often labeled "AT" or similar).
4. Change the value of the auto-tuning parameter to "1" (or "ON") using the ^ or v keys.
5. Press SET to confirm. The AT indicator will light up, and the controller will begin the auto-tuning process.
6. The system will cycle through heating and cooling to determine the optimal parameters. This process may take some time.
7. Once auto-tuning is complete, the AT indicator will turn off, and the controller will operate with the newly calculated PID parameters.

Figure 6: Intelligent Auto-tuning Principle

7. Maintenance

• Cleaning: Wipe the display and panel with a soft, dry cloth. Do not use abrasive cleaners or solvents.
• Environmental Conditions: Ensure the operating environment remains within specified ranges (0~50°C, 35–85% RH, no corrosive gases or strong EM radiation).
• Connection Checks: Periodically inspect wiring connections for looseness or corrosion.
• Sensor Integrity: Ensure the external temperature sensor is clean and undamaged for accurate readings.

8. Troubleshooting

• No Display/Power:
  • Check power supply connections and voltage.
  • Ensure the power switch (if external) is ON.
• Inaccurate Temperature Reading (PV):
  • Verify the external sensor is correctly connected and not damaged.
  • Ensure the sensor type configured in the controller matches the actual sensor used.
  • Check for environmental interference (e.g., strong electromagnetic fields).
• Temperature Not Reaching Set Value (SV) or Unstable:
  • Confirm the output wiring to the heating/cooling element is correct and the element is functioning.
  • Perform PID auto-tuning to optimize control parameters for your system.
  • Check if the control output indicator (OUT1) is active when expected.
• Alarm Not Functioning:
  • Verify alarm settings (e.g., high/low limit, deviation).
  • Check wiring to the alarm device.

9. User Tips

• Sensor Selection: Always choose an external temperature sensor (thermocouple or RTD) that is appropriate for your specific temperature range and application. The controller itself does not measure temperature directly.
• Customization: If your application requires specific panel sizes, input types, or output configurations beyond the standard REX-C700 (72x72mm, K-type input, Relay/SSR output), contact the manufacturer for customized solutions. Other models like REX-C100 (48x48mm), REX-C400 (96x48mm), and REX-C900 (96x96mm) are also available.
• Initial Setup: For best performance, always perform PID auto-tuning after initial installation or significant changes to your heating/cooling system. This optimizes the controller's response.

10. Warranty and Support

This product is manufactured under strict quality control standards. For warranty information, technical support, or inquiries regarding custom configurations, please contact CERTEON customer service or your local distributor.

For technical consultations or bulk orders, you may contact:

• Email: celiachen008@gmail.com
• WhatsApp: +86-19542723588