C21 PID Temperature Controller
C21 $289.00 Excl. GST
Back to products
SR23A High Accuracy Digital Controller (96 x 96mm)
SR23A $0.00 Excl. GST
C91 PID Temperature Controller
C91 Digital Controller - Side View
C91 - Image 3
Click to enlarge
C91 PID Temperature Controller
C91 Digital Controller - Side View
C91 - Image 3

C91 – 48 x 48mm Digital Controller

Brand:

$289.00 Excl. GST

Select Power Input *

Signal Input *

Output 1 *

Output 2 *

Communications *

Display Colour *

Total: $289.00

All prices are in NZ$, and GST exclusive and are subject to change without notice.

Product Details

C91 PID Temperature Controller | 1/16 DIN PID Solution

The BrainChild C91 Temperature Controller is a compact, high-performance 1/16 DIN controller designed for precise temperature management in industrial automation. Equipped with fuzzy logic auto-tuning PID, it adapts intelligently to process changes, ensuring accurate and stable control.

The C91 supports a wide range of universal input types (TC, RTD, mV, mA) with 18-bit A/D resolution and a fast 5Hz sampling rate. Output configurations include relay, SSR, or analogue retransmission, making it suitable for both heating and cooling applications. Its built-in RS-232/RS-485 Modbus RTU, intuitive 4-key interface, and USB programming port offer seamless system integration and quick setup.

Panel Interface｜LED Display & 4-Key Control

The C91 temperature controller features a simple and functional panel interface designed for quick operation in compact control environments. A 4-digit red LED display provides clear real-time feedback of process values, setpoints, and control status.

Five status indicators on the panel signal essential operating modes:

  • Process Unit Indicator
  • Auto-Tuning Status
  • Manual Mode
  • Deviation Display
  • Output Activation

The device includes 4 tactile membrane buttons for easy configuration of setpoints, parameters, and mode selection, enhancing usability and minimizing setup time.

Input Specs｜Multi-Signal A/D Accuracy

The C91 temperature controller offers flexible universal input compatibility, supporting thermocouples (J, K, T, E, N, R, S), RTDs (PT100 DIN/JIS), and analog signals including 0–50 mV, 0–20 mA, 4–20 mA, 1–5V.

With a high-performance 18-bit A/D converter, it delivers precise readings across all signal types. The input circuit features cold junction compensation, digital filtering, and sensor break detection to ensure measurement stability and safety.

Output Options｜Relay, SSR or Analogue

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

The C91 controller provides flexible dual-output configurations, allowing users to select from relay contacts (2A/240VAC), SSR voltage drive, or analog outputs (0–20 mA, 4–20 mA, 0–10V, 1–5V).

The analogue output features 15-bit D/A resolution, ensuring high signal fidelity. Outputs can be assigned for PID control, alarm signalling, or dwell timer operation, depending on system setup.

C91 Features

  • Fuzzy PID with auto-tune control
  • Dual output: Relay, SSR or Analogue
  • 5Hz sampling rate for fast signal response
  • Supports TC, RTD, mV, mA, and voltage inputs
  • Bright 4-digit LED display for clear readout
  • Digital filter to stabilize fluctuating signals
  • Output 2 can be set as dwell timer function
  • Configurable alarm: high, low, band, dwell
  • Built-in Modbus RTU via RS-232 or RS-485
  • Relay, SSR, or analogue output options

Technical Specs

Power
90 – 250 VAC, 47 – 63 Hz, 10VA, 5W maximum
111 – 26 VAC / VDC, SELV, Limited Energy, 10VA, 5W maximum

 

Input 1 Characteristics
Resolution 18 bits
Sampling Rate 5 times / second
Maximum Rating -2 VDC minimum, 12 VDC maximum ( 1 minute for mA input )
Temperature Effect ±1.5 uV/ °C for all inputs except mA

input ±3.0 uV/ °C 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 200nA
Common Mode Rejection Ratio ( CMRR ) 120dB
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.

 

TYPE Range Accuracy@25°C Input Impedance
J -120°C -1000°C (-184°F -1832°F) ±2°C 2.2MΩ
K -200°C -1370°C (-328°F -2498°F) ±2°C 2.2MΩ
T -250°C -400°C (-418°F -752°F) ±2°C 2.2MΩ
E -100°C -900°C (-148°F -1652°F) ±2°C 2.2MΩ
B 0°C -1820°C (32°F -3308°F) ±2°C (200°C – 1820°C) 2.2MΩ
R 0°C-1767.8°C (32°F -3214°F) ±2°C 2.2MΩ
S 0°C -1767.8°C (32°F -3214°F) ±2°C 2.2MΩ
N -250°C -1300°C (-418°F -2372°F) ±2°C 2.2MΩ
L -200°C -900°C (-328°F -1652°F) ±2°C 2.2MΩ
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 -8mV -70mV ±0.05% 2.2MΩ
mA -3mA -27mA ±0.05% 70.5Ω
V -1.3V-11.5V ±0.05% 302KΩ

 

Output 1 / Output 2
Relay Rating 2A/240 VAC, life cycles 200,000 for resistive load
Pulsed Voltage Source Voltage 5V, current limiting resistance 66

 

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 10KΩ min.
1-5 V 0.9-1 V 5-5.25 V 10KΩ min.
0-10 V 0 V 10-10.5 V 10KΩ min.

 

Linear Output
Resolution 15 bits
Output Regulation 0.01 % for full load change
Output Settling Time 0.1 sec. ( stable to 99.9 % )
Isolation Breakdown Voltage 1000VAC
Temperature Effect ±0.0025 % of SPAN / °C

 

Triac ( SSR ) Output
Rating 1A / 240 VAC
Inrush Current 20A for 1 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 )
Alarm Functions Dwell timer,
Deviation High / Low Alarm,
Deviation Band High / Low Alarm
Process High / Low Alarm
Alarm 1 Relay Form A,Max. rating 2A/240VAC, life cycles 200,000 for resistive load.
Alarm Mode Normal, Latching, Hold, Latching / Hold.
Dwell Timer 0.1 – 4553.6 minutes

 

Data Communication
Interface RS-232 ( 1 unit ), RS-485 ( up to 247 units )
Protocol Modbus Protocol RTU mode
Address 1 – 247
Baud Rate 0.3 ~ 38.4 Kbits/sec
Data Bits 7 or 8 bits
Parity Bit None, Even or Odd
Stop Bit 1 or 2 bits
Communication Buffer 50 bytes

 

Analog Retransmission
Output Signal 4-20 mA, 0-20 mA, 0-1V, 0-5V, 1-5V, 0-10V
Resolution 15 bits
Accuracy ±0.05 % of span ±0.0025 %/ °C
Load Resistance 0 – 500 ohms ( for current output ),10 K ohm minimum ( for voltage output )
Output Regulation 0.01 % for full load change

 

User Interface
Single 4-digit LED Displays 10mm
Keypad 4 keys
Programming Port For automatic setup, calibration and testing
Communication Port Connection to PC for supervisory control

 

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 ~ 500.0 °C ,
Integral time 0 – 1000 seconds , Derivative time 0 – 360.0 seconds
Cycle Time 0.1 – 100.0 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 ~ 900.0°F/minute or 0 ~ 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 & Physical
Operating Temperature -10°C ~ 50°C
Storage Temperature -40°C ~ 60°C
Humidity 0 to 90 % RH ( non-condensing )
Insulation Resistance 20 Mohms min. ( at 500 VDC )
Dielectric Strength 2000 VAC, 50/60 Hz for 1 minute
Vibration Resistance 10 – 55 Hz, 10 m/s² for 2 hours
Shock Resistance 200 m/s2( 20 g )
Moldings Flame retardant polycarbonate
Dimensions C91 —48mm(W) X 48mm(H) X 94mm(D), 86 mm depth behind panel
Mounting C91 —panel mount, cutout 45 X 45 ( mm )
Weight C91 — 140 grams
Altitude 2000m maximum

 

Approval Standards
Safety UL 61010C-1 , CSA C22.2 No. 24-93 , EN61010-1 (IEC1010-1)
Protective Class NEMA 4X ( IP65 ) front panel for C21,
IP30 front panel for C91, all indoor use,
IP20 housing and terminals
EMC EN61326

Ordering Information

C91-(1)-(2)-(3)-(4)-(5)-(6)
 Power Input4: 90 - 250 VAC, 47-63 HZ
5: 11 - 26 VAC or VDC, SELV, Limited Energy
2 Signal Input1: Standard Input
Thermocouple: J, K, T, E, B, R, S, N, L
RTD: PT100 DIN, PT100 JIS 
2: 0 - 60 mV
3: 0 - 1 V
4: 0 - 5 V
5: 1 - 5 V
6: 4 - 20 mA
7: 0 - 20 mA
8: 0 - 10V
9: Special Order
3 Output 10: None
1: Relay rated 2A / 240VAC
2: Pulsed voltage to drive SSR, 5V / 30mA
3: Isolated 4 - 20mA / 0 - 20mA
4: Isolated 1 - 5V / 0 - 5V
5: Isolated 0 - 10V
6: Triac output 1A / 240VAC,SSR
C: Pulsed voltage to drive SSR, 14V/40mA
9: Special order
4 Output 20: None
1: Form A relay 2A / 240VAC
2: Pulsed voltage to drive SSR, 5V / 30mA
3: Isolated 4 - 20mA / 0 - 20mA
4: Isolated 1 - 5V / 0 - 5V
5: Isolated 0 - 10V
6: Triac output, 1A / 240VAC, SSR
7: Isolated 20V / 25mA transducer power supply
8: Isolated 12V / 40mA transducer power supply
9: Isolated 5V / 80mA transducer power supply
A: RS-485 interface
C: Pulsed voltage to drive SSR, 14V/40mA
D: Retransmit 4-20mA / 0-20mA
E: Retransmit 1-5V / 0-5V
F: Retransmit 0-10V
B: Special order
5 Communications0: None
1: RS-485 interface
9: Special order
6 Display Color0: Red color
1: Green color

Documents