PID Controllers-Single and Two Loops (Microcontroller Based)
Product Specification :
Model wise descriptions :
|PID-723-U||PID Controller (Universal Input)||72 x 72 x 120|
|PID-966-U||PID Controller (Universal Input)||96 x 96 x 120|
|PID-948-U||PID Controller (Universal Input)||96 x 48 x 110|
|PID-489-U||PID Controller (Universal Input)||48 x 96 x 110|
|PID-723-F||PID Controller (Fixed Input)||72 x 72 x 120|
|PID-966-F||PID Controller (Fixed Input)||96 x 96 x 120|
|PID-948-F||PID Controller (Fixed Input)||96 x 48 x 110|
|PID-489-F||PID Controller (Fixed Input)||48 x 96 x 110|
|PID-966-T||PID Controller with (Two fixed input)||96 x 96 x 120|
Libratherm offers Four new models of PID controllers ,Model PID-723,PID-966,PID-948 and PID-489. These are designed and developed using the latest microcontroller chip and programmed with the time tested and field proven PID algorithm. PID controllers are mainly used for the precise process control. Unlike On/Off type of oscillatory control, PID control action gives smooth and steady state control. These model offers, all the useful features which are required to control the complex system.
These models accept factory set single or dual fixed input or the user selectable universal input. The control action is user selectable as PID or On/Off for both direct and reverse or Heat and Cool action . Control outputs are given in the form of optically isolated DC pulse to drive external SSR, Triac or AC SSR to operate AC operated load, electro mechanical relay and/or linear analog output. The analog output levels can also be configured for (0-20)mA or (4-20)mA or (0-5) / (0-10) volt using the front panel key board,
In brief, PID-723, PID-948 and PID-489 provides 4 switching outputs and 2 analog outputs whereas PID-966 provides 6 switching and two analog outputs. Both Auto and manual tuning of PID values makes the controller versatile and user friendly. The model PID-723,PID-948 and PID-489 being small in size, can easily be accommodated in small size equipments. One Ramp/Soak function allows user to gradually increase the set value and hold the process value for desired soak time.
These models are only designed to accept two independent input sensor, which avoids the need for two controllers, where the space and cost is the constraint. This feature is useful for system where two sensors are used for controlling two independent loads, as in case of strip / blister packaging machines where two heaters are to be controlled and each heater has individual sensor
Libratherm also offers customized algorithm for special purpose applications, where user or OEM wants to have control and logic action to suit their application.
PID Controller with Universal / Fixed Input and Selectable Outputs:
Such controllers are used for single input with onsite facility to select the desired input type, but output can be selected as desired.
PID Controller with Two Inputs And Two Outputs
Such controllers are mainly used for single system having two same type of sensors and two independent control outputs. Or to use One input as indication only and other input for controlling.
• Microcontroller based design.
• Single loop PID function.
• One Ramp/Soak feature (user programmable).
• Available Control - Two logic (DC pulse) and Two analog (12 bit resolution).
• Auto/Manual tuning of PID parameters.
• Field proven Algorithm tested successfully for various process control applications.
• Auto/Manual bump less transfer.
• Two programmable alarms and / or event relay outputs.
• Furnace / Oven Temperature control
• Pressure control
• Constant Temperature Bath
• Cold storage and Chilling plants
• Laboratory equipment.
• Plastic Injection, Extruder machines
• Material Testing equipments
• Auto Clave, BOD incubator
Technical specifications :
The following specifications will suit almost all PID control applications – however, for special PID algorithm for controlling modulating motorized valve refer to the model PID-966-M.
|Input -U (Universal)||RTD(Pt-100) and Thermocouple (type J,K,R,S,B), V and mA (ie Maximum 8 user selectable inputs using keyboard and DIP switch on the back panel) in Universal model. In two input model both the inputs are of same type. Other fixed inputs can also be provided as per the range selection table.|
|Input –F (Fixed)||Any one factory set input as per user’s requirement. It is not possible to change the type of input on the field.|
|Input – T (Two)||Two fixed inputs of similar types – but factory set input as per user’s requirement.|
|Range||Full +ve range of the selected input
(please refer to the range selection table in PDF)
|Resolution||1 oC for thermocouples and 0.1oC for Pt-100 for V and mA inputs the display resolution is subject to the required range.
For V and mA input the position of the decimal point can be selected.
|Sampling rate / Display rate||The input is read @40mS / the display is updated @1 second. The control loop is also executed @ 40 ms.|
|Indicating Accuracy||+/- 1 oC for Thermocouple throughout the range and
+/- 0.1oC for Pt-100 for (4-20)mA or (0-10)V - absolute to the linear input signal
|One Ramp / Soak (Optional1)||To Gradually increase the process value –
Ramp rate : rt = 0.0 to 100.0oC/min or 0 to 100oC/min
To Hold the controlled process value for required time,
Soak time : St = 0 to 999 minutes.
|Display (PID-723)||4 digit 0.3" Red 7-segment display for process variable.
4 digit 0.3" Red 7-segment display for set value and PID parameters
|Display (PID-966)||4 digit 0.5" Red 7-segment display for process variable .
4 digit 0.5" Green 7-segment display for set value and PID parameters
|Display (PID-948)||4 digit 0.2" Red 7-segment display for process variable.
4 digit 0.2" Green 7-segment display for set value and PID parameters
|Display (PID-489)||4 digit 0.2" Red 7-segment display for process variable .
4 digit 0.2" Green 7-segment display for set value and PID parameters
|Output Indication||Front Panel LED indications for Control Output, Alarms, Control and A/M status|
|Control Algorithm||PID or ON/OFF selectable (when specified for switching output).
Direct action or Reverse action or both (to be specified in the ordering information)
Reverse Action is considered as Heat output – where control output decreases as the error (SV-PV)s is less positive and vice versa.
Direct Action is considered as Cool output – where control output increases as the error (PV-SV) is more positive and vice versa.
|Tuning||Auto/Manual tuning of PID values.|
|PID Values||Proportional Band (P)= 0.0 to 100.0% of Span, Integral (I)= 0.00 to 5.00 resets/minute, Derivative (D) = 0.00 to 5.00miutes, Hysterisis = 0 to 50 counts, Cycle Time = 2 to 100 seconds.|
|Settings||Using front panel feather touch (metal dome) key board to set various parameters.|
|Remote Set point (Optional2)||External (4-20)mA input can be used to vary the set point in the range of manual mode. (Local or remote set point is user selectable – remote set point to be enabled for this feature)
(facility only in PID-966).
|Memory Backup||Retention of PID and Set values in the built in non-volatile memory - in case of power failure and automatic re-execution of control on power resumption.|
|Control Outputs (Switching)||Switching Outputs - DC pulse (0 to 10VDC@25mA) for external SSRs.
Relay or Triac (AC SSR) (rated for 5A @230VAC) for external contactor.
(Dual switching outputs available in model PID-966-T).
|Control Outputs (Analog)||Analog Outputs (4-20)mA (RL max = 300 Ohms) or 0-5VDC
(RL min = 10KOhms) (Dual Outputs available in model PID-966-T).
|Retransmission Output (Analog)||4-20mA non-isolated, linearized and proportional to the selected input type and range. (Dual retransmission outputs can be provided when not used as control outputs for PID-966-T). RL max = 300 Ohms.|
|Alarm Outputs||2 extra Relay Outputs with programmable hysteresis- can be used as High or Low Alarms.|
|Serial Communication (Optional 3)||Optically isolated 2 wire RS485 on Modbus RTU protocol. (in Slave mode with programmable modbus address).|
|Loop Supply (Optional4)||Isolated 18 to 24VDC @ 50 mA to power external two wire loop transmitter ( PID-966)|
|Supply||(90VAC-250VAC), 50/60 Hz|
|Size||72 x 72 x 120 mm.(PID-723)
96 x 96 x 120 mm (PID-966)
96 x 48 x 110 mm.(PID-948)
48 x 96 x 110 mm.(PID-489)
|Panel Cutout / Terminals||68 x 68 mm. +/- 0.5 mm. (PID-723) - 18 back panel terminals
92 x 92 mm +/- 0.5 mm. (PID-966) - 26 back panel terminals
92 x 44 mm. +/- 0.5 mm. (PID-948) - 22 back panel terminals
44 x 92 mm +/- 0.5 mm. (PID-489) - 22 back panel terminals
|Enclosure||ABS plastic with polycarbonate front graphic.|