Digital Temperature Controller Reference Manual
Digital Temperature Controller Reference Manual Digital Temperature Controller Reference Manual
Figure 2-3 Software temperature control loop TECHNICAL DESCRIPTION DIGITAL TEMPERATURE CONTROLLER REFERENCE MANUAL 2-6
2.4.1.2 Spike integral block TECHNICAL DESCRIPTION The integral control block brings the temperature back to the setpoint. If there is an error, this block will make long term adjustments to the power. An increase in the integral parameter will decrease the amount of change in the (current controlling) output. The inputs to this block are the P.D. output and the Integral parameter. Every second the P.D output is divided by the Integral parameter value. This is then added to or subtracted from the integral output, depending on the sign of the input. The maximum value is equal to the proportional band value and the minimum is zero. This final value is added to the P.D. output to give the D.I. output. 2.4.1.3 Spike proportional block The proportional control is used to create a bandwidth around the controlling setpoint. The proportional parameter will be the bandwidth at which maximum power will be applied. Proportional control always gives an offset between setpoint and actual temperature. This offset is needed to apply the power and is dependent on the proportional parameter and the amount of power needed to maintain the power. If the proportional bandwidth is too small, oscillation of the control loop can occur. The inputs to this block are the D.I. output and the proportional parameter (in degrees). The output is obtained by dividing the D.I. output by the proportional parameter and then multiplying by 100. This gives a percentage output (P.I.D). 2.4.1.4 Spike gain block The gain block limits the maximum output power and is used to stop the controller oscillating. This is of particular importance at low temperatures. The control loop gives the best response if the power required to maintain the temperature is 35-45% of the maximum power. This block converts the percentage P.I.D. output into a scale related to the gain parameter value. During the ramping up of a zone, the gain parameter extracted from the parameter table is increased in relation to the slope of the ramp. If the temperature is below setpoint, the gain value is increased to compensate for the deficiency. The maximum value of the gain parameter is 98. 2.4.1.5 Main and side zone gain blocks The main and side zone gain blocks are used for broadband conveyor furnaces. The three gain blocks translate the gain controlled PI.D output into three gain controlled power outputs. The input multiplied by the programmed gain value of the control zone divided by one hundred gives the current power output value. The maximum power value is 98%. The output is converted to proportioned on-off for the SCR or triac drivers. 2.4.2 Paddle control The paddle D.I. control is only active if the zone is programmed for control on the paddle thermocouple and is only of interest in a diffusion furnace. The output of the D.I. control is used to modify the setpoint for the spike control loop. These modifications will be in response to the temperature variations inside the tube. DIGITAL TEMPERATURE CONTROLLER REFERENCE MANUAL 2-7
- Page 1 and 2: Digital Temperature Controller Refe
- Page 3 and 4: Table of Contents TABLE OF CONTENTS
- Page 5 and 6: List of figures LIST OF FIGURES Fig
- Page 7 and 8: HIGH ACCURACY THERMOCOUPLE CONTROL
- Page 9 and 10: 1.4 Technical Specifications MAX. N
- Page 11 and 12: 2.Technical Description 2.1 Introdu
- Page 13 and 14: TECHNICAL DESCRIPTION Communication
- Page 15: TECHNICAL DESCRIPTION A maximum of
- Page 19 and 20: 3.DTC Configuration 3.1 Introductio
- Page 21 and 22: 3.3 Conveyer furnaces DTC CONFIGURA
- Page 23 and 24: 4.Installation and Calibration 4.1
- Page 25 and 26: STEP 1: INSTALLATION AND CALIBRATIO
- Page 27 and 28: NOTE INSTALLATION AND CALIBRATION M
- Page 29 and 30: 4.3 Repair INSTALLATION AND CALIBRA
2.4.1.2 Spike integral block<br />
TECHNICAL DESCRIPTION<br />
The integral control block brings the temperature back to the setpoint. If there is an error,<br />
this block will make long term adjustments to the power. An increase in the integral<br />
parameter will decrease the amount of change in the (current controlling) output.<br />
The inputs to this block are the P.D. output and the Integral parameter. Every second the<br />
P.D output is divided by the Integral parameter value. This is then added to or subtracted<br />
from the integral output, depending on the sign of the input. The maximum value is equal to<br />
the proportional band value and the minimum is zero. This final value is added to the P.D.<br />
output to give the D.I. output.<br />
2.4.1.3 Spike proportional block<br />
The proportional control is used to create a bandwidth around the controlling setpoint. The<br />
proportional parameter will be the bandwidth at which maximum power will be applied.<br />
Proportional control always gives an offset between setpoint and actual temperature. This<br />
offset is needed to apply the power and is dependent on the proportional parameter and the<br />
amount of power needed to maintain the power. If the proportional bandwidth is too small,<br />
oscillation of the control loop can occur.<br />
The inputs to this block are the D.I. output and the proportional parameter (in degrees). The<br />
output is obtained by dividing the D.I. output by the proportional parameter and then<br />
multiplying by 100. This gives a percentage output (P.I.D).<br />
2.4.1.4 Spike gain block<br />
The gain block limits the maximum output power and is used to stop the controller<br />
oscillating. This is of particular importance at low temperatures. The control loop gives the<br />
best response if the power required to maintain the temperature is 35-45% of the maximum<br />
power.<br />
This block converts the percentage P.I.D. output into a scale related to the gain parameter<br />
value. During the ramping up of a zone, the gain parameter extracted from the parameter<br />
table is increased in relation to the slope of the ramp. If the temperature is below setpoint,<br />
the gain value is increased to compensate for the deficiency. The maximum value of the gain<br />
parameter is 98.<br />
2.4.1.5 Main and side zone gain blocks<br />
The main and side zone gain blocks are used for broadband conveyor furnaces. The three<br />
gain blocks translate the gain controlled PI.D output into three gain controlled power<br />
outputs. The input multiplied by the programmed gain value of the control zone divided by<br />
one hundred gives the current power output value. The maximum power value is 98%. The<br />
output is converted to proportioned on-off for the SCR or triac drivers.<br />
2.4.2 Paddle control<br />
The paddle D.I. control is only active if the zone is programmed for control on the paddle<br />
thermocouple and is only of interest in a diffusion furnace. The output of the D.I. control is<br />
used to modify the setpoint for the spike control loop. These modifications will be in<br />
response to the temperature variations inside the tube.<br />
DIGITAL TEMPERATURE CONTROLLER REFERENCE MANUAL 2-7
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