1. Home
  2. Products
  3. Controllers
  4. Classic Premium Series
  5. Classic Premium Series | 50 x 26mm  C21

Classic Premium Series | 50 x 26mm

C21
https://www.brainchildtw.com/web/image/product.template/65/image_1920?unique=74d9fbf

PID Temperature controller

• Auto-tune fuzzy PID control
• High-accuracy 18-bit A/D input
• Compact 1/32 DIN panel size
• RS-485 / RS-232 communication
• Lockout & alarm safety control

This combination does not exist.

Features Applications Specification Download FAQ Ordering Code

Features

  • Bright 4-digit LED with easy-to-read display
  • Compact 1/32 DIN size for space-saving panels
  • Supports thermocouples & RTD (PT100) input
  • High-accuracy 18-bit A/D input resolution
  • 15-bit D/A analog output with stable performance
  • Fast 5 samples/sec A/D conversion rate
  • 2A relay or SSR voltage output selectable
  • Programmable ramping and dwell time
  • Auto/manual mode with bumpless transfer
  • Wide-range alarms: high, low, band, dwell
  • Lockout security with multiple access levels
  • Digital filter for steady temperature display
  • Soft-start ramping on power-up
  • RS-485/232 communication + PC setup port
  • CE, UL, CSA approvals with NEMA 4X / IP65 panel

C21 Temperature Controller | Compact PID Control

1/32 DIN size with auto-tuning fuzzy PID and RS-485  

The BrainChild C21 Temperature Controller is a 1/32 DIN compact PID controller designed for precise thermal process management in space-limited industrial applications. Featuring auto-tuning fuzzy logic, it adapts dynamically to process changes while maintaining stable and accurate temperature control.

With a bright 4-digit LED display, fast 18-bit A/D conversion, and options for relay or SSR output, the C21 provides the ideal balance of performance and size. It also supports RS-232/485 communication and comes with multiple alarm configurations and soft-start ramping to ensure reliable, secure operation.

 


Panel Interface｜LED Display with 3-Key Control

Compact front panel with intuitive control and status visibility  

The C21 temperature controller features a compact and efficient front panel interface built for simplicity and ease of use. At the center is a bright 4-digit red LED display, offering clear visibility of current process values and setpoints even in dim environments.

Below the display are three responsive silicone rubber keys designed for quick navigation, parameter setting, and control mode switching. The tactile feel ensures reliable feedback during setup or runtime adjustment, minimizing errors in industrial conditions.

The compact layout fits standard 1/32 DIN panel cutouts, making the C21 ideal for space-constrained equipment while maintaining full functionality and safety visibility. 

Input Specs｜Universal Thermocouple & RTD

Supports high-accuracy TC, RTD, mV, mA inputs with 18-bit A/D  

The C21 temperature controller accepts a wide range of universal input signals, including thermocouples (J, K, T, E, N, R, S) and RTDs (PT100 DIN/JIS). It also supports analog signals such as 0–50 mV, 0–20 mA, 4–20 mA, with flexible scaling and cold junction compensation.

A high-resolution 18-bit A/D converter ensures accurate process monitoring, while a fast 5 samples/second sampling rate provides responsive control for dynamic applications. The input circuit features built-in sensor break detection for added safety.

 

Output Options｜Relay, SSR & Analog Ready  

Selectable relay, SSR voltage or 15-bit analog output for control

The C21 offers flexible output configurations to meet various control needs. Depending on model and settings, users can choose from:

  • Relay contact output: rated 2A/240VAC for on/off control

  • SSR drive voltage output: for external solid-state relay triggering

  • Analog retransmission output: 0–20 mA, 4–20 mA, 0–10V with 15-bit D/A resolution

This output flexibility makes the C21 ideal for use in heating, cooling, or alarm control applications. Each output channel can be assigned to control, alarm, or retransmission functions based on system setup.

Fuzzy PID Technology   

Smarter Control with Less Overshoot and Faster Response  

Fuzzy logic is combined with traditional PID control to deliver smarter and more adaptive temperature regulation. Unlike standard PID controllers that require manual fine-tuning for each application, fuzzy PID dynamically adjusts control responses based on real-time process behavior. The result is faster stabilization, reduced overshoot, and improved resilience to disturbances—ideal for processes where precision and speed are critical.

Built-in Programming Port for Fast Configuration

PC interface for configuration, parameter upload, and calibration

The C21 temperature controller features a convenient programming port that allows users to connect the unit to a PC via USB interface for fast configuration. Using the compatible setup software, users can easily perform parameter upload/download, firmware updates, and system calibration without manual keypad entry.

This function is ideal for batch setup, production line tuning, or simplifying field maintenance. The port ensures consistent configuration across multiple units and helps reduce setup time and human error. 

BC-SET Pro Configuration Software

Easy parameter setup, backup and firmware upgrade

BC-SET Pro is the official configuration software developed by BrainChild for its over-temperature protection controllers. With a streamlined and intuitive interface, the software allows users to connect via USB programming cable and quickly configure control parameters. It supports efficient parameter editing, setting duplication between devices, and firmware upgrades to maintain device performance and stability. BC-SET Pro also enables offline configuration with the ability to save and manage multiple profiles, making it ideal for production environments, system deployment, and ongoing maintenance. Whether for new setup or existing system adjustment, this tool helps engineers and technicians simplify workflow, reduce setup time, and ensure consistent configuration across all devices.  

Batch Read/Write for Multiple Controllers 

BC-SET allows users to connect multiple controllers of the same model and perform batch parameter read/write by defining a node address range. This feature significantly streamlines configuration in OEM or multi-device environments.

Clear and Accessible System Menu 

The system menu offers quick access to key operations like Rescan (F5), Read Data (F6), Write Data (F7), Write Multiple (F8), and Communication Settings (F9). Built-in hotkeys support fast, efficient navigation.

Intuitive Communication Setup Interface

The communication settings window lets users define COM port, baud rate, parity, data bits, and stop bits — with a “Default” button for quick reset and “Save and Exit” to finalize setup. Designed to reduce setup errors.

Visual Profile Editor for Programmable Controllers 

For controllers with profile functionality, BC-SET provides a graphical editor to configure temperature ramp/soak segments. Users can easily read, modify, and write profile parameters for precise thermal process control.

Protective Class｜Front Panel IP65 Rated

NEMA 4X and IP65-rated front panel for harsh environments  

The C21 temperature controller offers reliable environmental protection with its IP65 and NEMA 4X-rated front panel, making it suitable for installation in industrial environments exposed to dust, moisture, or light water jets. When properly installed with a waterproof gasket and mounting hardware, the front panel resists ingress from solids and liquids.

While the front is protected, the housing and terminals are rated for indoor use and should be enclosed in control cabinets to ensure safety. This protection level ensures long-term reliability, especially in food equipment, lab ovens, and packaging machinery.

Applications

Specification


 Power

90 - 250 VAC, 47 - 63 Hz, 10VA, 5W maximum

11 - 26 VAC / VDC, 10VA, 5W maximum
 Signal Input

Resolution

18 Bits

Sampling Rate

5 times / second

Maximum Rating

-2 VDC minimum, 12 VDC maximum( 1 minute for mA input )

Temperature Effect

±1.5uV/ BC for all inputs except mA input
±3.0uV/ BC for mA input

Sensor Lead Resistance Effect

T/C: 0.2uV/ohm
3-wire RTD: 2.6 °C/ohm of resistance difference of two leads
2-wire RTD: 2.6 °C/ohm of resistance sum of two leads

Burn-out Current

200nA

Common Mode Rejection Ratio(CMRR)

120 dB

Normal Mode Rejection Ratio (NMRR)

55dB

Sensor Break Detection

Sensor open for TC, RTD and mV inputs, Sensor short for RTD input, below 1 mA for 4 ~ 20 mA input, below 0.25V for 1 ~ 5 V input, unavailable for other inputs.

Sensor Break Responding Time

Within 4 seconds for TC, RTD and mV inputs, 0.1 second for 4 ~ 20 mA and 1 ~ 5 V inputs.

Input characteristics

 Type

Range

Accuracy @ 25°C

Input Impedance

J

-120°C  ~ 1000°C( -184°F ~ 1,832°F)

±2°C

2.2 MΩ

K

-200°C ~ 1370°C (-328°F ~ 2498°F)

±2°C

2.2 MΩ

T

-250°C ~ 400°C ( -418°F ~  752°F )

±2°C

2.2 MΩ

E

-100°C ~ 900°C( -148°F ~ 1652°F )

±2°C

2.2 MΩ

B

0°C ~ 1800°C( 32°F ~  3272°F )

±2°C( 200°C ~ 1800°C )

2.2 MΩ

R

0°C ~ 1767.8°C( 32°F ~ 3214°F )

±2°C

2.2 MΩ

S

0°C ~ 1767.8°C( 32°F ~ 3214°F )

±2°C

2.2 MΩ

N

-250°C ~ 1300°C( -418°F ~ 2372°F)

±2°C

2.2 MΩ

L

 -200°C ~ 900°C( -328°F ~ 1652°F )

±2°C

2.2 MΩ

PT100(DIN)

-210°C ~ 700°C( -346°F ~ 1292°F )

±0.4°C

1.3KΩ

PT100(JIS)

-200°C ~ 600°C( -328°F ~ 1112°F )

±0.4°C

1.3KΩ

mV

-8mA  ~ 70mA

±0.05%

2.2MΩ

mA

-3mA  ~ 27mA

±0.05%

70.5Ω

V

-1.3V  ~ 11.5V

±0.05%

650KΩ
Output 1  / Output 2

Relay Rating

2A,240V AC,200000 Life Cycles for Resistive Load

Pulsed Voltage

Source Voltage 5V, Current Limiting Resistance 66Ω

Linear Output Characteristics

Type

Zero Tolerance

Span Tolerance

Load Capacity

4 ~ 20 mA

3.6 ~ 4 mA

20 ~ 21 mA

500Ω max.

0 ~ 20 mA

0 mA

20 ~ 21 mA

500Ω max.

0 ~ 5 V

0 V

5 ~ 5.25 V

10 KΩ min.

1 ~ 5 V

0.9 ~ 1 V

5 ~ 5.25 V

10 KΩ min.

0 ~ 10 V

0 V

10 ~10.5 V

10 KΩ min.
Linear Output

Resolution

15 Bits

Output Regulation

0.02% for full load change

Output Settling Time

0.1 Second ( Stable to 99.9%)

Isolation Breakdown Voltage

1000 VAC

Temperature Effect

±0.01% of  Span/ °C
Triac ( SSR ) Output

Rating

1A / 240 VAC

Inrush Current

20A for a cycle

Min. Load Current

50 mA rms

Max. Off-state Leakage

3 mA rms

Max. On-state Voltage

1.5V rms

Insulation Resistance

1000 Mohms min. at 500 VDC

Dielectric Strength

2500 VAC for 1 minute
 Alarm (Output 2)

Relay Type

Form A

Maximum Rating

2A, 240VAC, 200000 Life Cycles for Resistive Load

Alarm Functions

Dwell Timer, Deviation Low, Deviation High, Deviation Band Low, Deviation Band High, Process High, Process Low

Alarm Mode

Latching, Hold, Normal, Latching/Hold

Dwell Timer

0.1 ~ 4553.6 Minutes
 Data Communication

Interface

RS-232 ( 1 unit ), RS-485 ( up to 247 units )

Protocol

Modbus RTU (Slave Mode)

Address

1 - 247

Baudrate

2.4KBPS ~ 38.4 KBPS

Data Bits

7 or 8 Bits

Parity Bit

None, Even or Odd

Stop Bit

1 or 2 Bits

Communication Buffer

160 Bytes
Analog Retransmission

Output Signal

4 ~20 mA, 0 ~ 20 mA,0 - 10V

Resolution

15 Bits

Accuracy

±0.05% of Span ± 0.0025% / °C

Load Resistance

0 to 500Ω for Current Output , 10KΩ minimum for Voltage Output

Output Regulation

0.01% for full load change

Output Setting Time

0.1 Second (Stable to 99.9%)

Isolation Breakdown

1000VAC minimum

Integral Linearity Error

±0.005% of Span

Temperature Effect

±0.0025% of Span /°C

Saturation Low

0mA or 0V

Saturation High

22.2mA or 5.55V,11.1V min

Linear Output Ranges

0 ~ 22.2mA (0 ~ 20mA / 4 ~ 20mA), 0 ~ 5.55V (0 ~ 5V, 1 ~ 5V),0 ~ 11.1V (0 ~ 10V)
User Interface

Keypad

4 Keys

Display Type

4 Digit LCD Display

No. of Display

3

Upper Display Size

0.98”(25mm)

Lower Display Size

0.55”(14mm)
Control Mode

Output 1

Reverse (Heating) or Direct (Cooling) Action

Output 2

PID cooling control, Cooling P band 50~300% of PB, Dead band -36.0 ~ 36.0 % of PB

ON-OFF

0.1 ~ 90.0 (°F ) hysteresis control ( P band = 0)

P or PD

0 ~ 100.0 % offset adjustment

PID

Fuzzy logic modified Proportional band 0.1 ~ 900.0°F, Integral time 0 ~ 3600 Seconds,Derivative time 0 ~ 360.0 Seconds

Cycle Time

0.1 ~ 90.0 Seconds

Manual Control

Heat(MV1) and Cool(MV2)

Auto-tuning

Cold Start and Warm Start

Failure Mode

Auto transfer to manual mode while sensor break or A-D Converter damage

Ramping Control

0 to 900.0°F/Minute or 0 to 900.0°F/Hour Ramp Rate
Digital Filter

Function

First Order

Time Constant

0,0.2, 0.5, 1, 2, 5, 10, 20, 30, 60 Seconds Programmable
 Environmental and Physical Specifications

Operating Temperature

-10°C ~ 50°C

Storage Temperature

-40°C ~ 60°C

Humidity

0 ~ 90 % RH (Non-Condensing)

Altitude

2000 Meters maximum

Pollution

Degree II

Insulation Resistance

20MΩ minimum(@500VDC)

Dielectric Strength

2000VAC,50/60 Hz for 1 Minute

Vibration Resistance

10 to 55 Hz , 10m/s2 for 2 Hours

Shock Resistance

200 m/s2(20g)

Moldings

Flame Retardant Polycarbonate

Mounting

Panel

Dimensions (W*H*D) (mm)

50*26.5*110.5

Depth Behind Panel (mm)

90

Cut Out Dimensions (mm)

22*45

Weight (grams)

120
Approval Standards

Safety

UL61010C-1, CSA C22.2 No.24-93, EN61010-1 ( IEC1010-1 )

Protective Class

IP65 for Panel,IP20 for terminals and housing, all indoor use

EMC

EN61326

Download

C21&C91_Brochure_092826_EN

C21&C91_Brochure_101108_CH
C21&C91_UserManual_UM0C911H_EN
Software_BC_Set_2.0​
Software_BC_Set_Pro_V1.1.0.12​(Firmware above V33)

C21&C91_UsersManual_UM0C911H_EN

Data_Logger_Firmware_XH10_v1.1.0.34​

Software_BC_Set_Pro_V1.1.0.12_2.0​
Software_DAQ_V2.73(2501)*1-hour trial only

Training_Demo_Data_Acquistion_Studio

UMEIO01A​
UMEIO01A​

IO_Brouchure_Ver.1.4/

Visit Download Center to See More Documents & Tools of This Product.     Visit

FAQ

What size is the C21 controller, and where can it be installed?

The C21 features an ultra-compact 1/32 DIN panel size, making it ideal for space-limited applications like laboratory ovens, panel meters, and compact machinery.  

Does the C21 support auto-tuning for PID control?

Yes. The C21 includes auto-tuning with fuzzy logic to automatically optimize PID parameters based on process behavior, ensuring stable temperature control with minimal overshoot.

What types of input signals can the C21 accept?

The C21 supports thermocouples (J, K, T, E, N, R, S), RTDs (PT100 DIN/JIS), and analog inputs such as 0–50 mV, 0–20 mA, and 4–20 mA, providing flexibility for various sensor types.  

Does the C21 provide communication capabilities for integration?

Yes. The C21 supports RS-485 and RS-232 communication protocols and offers a programming port for PC-based parameter setup, making it easy to integrate into SCADA or automation systems.  

What level of protection does the C21 provide for harsh environments?

The front panel of the C21 is IP65 and NEMA 4X rated, providing protection against dust, moisture, and water splashes. The unit must be panel-mounted with proper sealing to maintain this rating.  

Ordering Code

單獨的電子郵件地址用逗號區分.
Submit
將其替換為您自己的 HTML 代碼