Menu 14 − User PID Controller

Mode: RFC‑A

PID controllers

One general purpose PID controllers is provided as shown in the diagram below. The sample rate for the PID controllers is always 4ms.


Parameter14.001  PID1 Output
Short descriptionDisplays the output for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

Controller

The controller section for the PID controllers is shown in the introduction. If the enable is active the PID controller is active even if the destination is not routed to a valid parameter or to 0.000. It should be noted that if either of the enable sources is routed to 0.000 or to a non-valid parameter the source value is taken as 1, therefore with default settings, PID1 Enable Source 1  (14.009) = 0.000 and PID1 Enable Source 2  (14.027) = 0.000, the PID controller can be enabled by simply setting PID1 Enable  (14.008).

PID1 Error  (14.022) is the difference between the reference and feedback produced by the reference and feedback systems described in the previous sections. The PID controller output is defined as follows:

PID1 Output  (14.001) = PID1 Error  (14.022) x [Kp + Ki/s + sKd/(0.064s + 1)]

Kp = PID1 Proportional Gain (14.010)

Ki = PID1 Integral Gain  (14.011)

Kd = PID1 Differential Gain  (14.012)

Therefore:

1. If PID1 Error  (14.022) = 100.00% the proportional term gives a value of 100.00% if PID1 Proportional Gain (14.010) = 1.000.

2. If PID1 Error  (14.022) = 100.00% the integral term gives a value that increases linearly by 100.00% per second if PID1 Integral Gain  (14.011) = 1.000.

3. If PID1 Error  (14.022) increases linearly by 100.00% per second the differential term gives a value of 100.00% if PID1 Differential Gain  (14.012) = 1.000. (A filter with a time constant of 64ms is provided on the differential gain to reduce the noise produced by this term.)

The output may be limited to a range that is less than the maximum range of PID1 Output  (14.001) using PID1 Output Upper Limit  (14.013) and PID1 Output Lower Limit (14.014). If PID1 Output Lower Limit (14.014) > PID1 Output Upper Limit  (14.013) then the output is held at the value defined by PID1 Output Upper Limit  (14.013). If PID1 Symmetrical Limit Enable  (14.018) = 1 then the lower limit = -(PID1 Output Upper Limit  (14.013)). If the output reaches either of these limits the integral term accumulator is frozen until the output moves away from the limit to prevent integral wind-up. The integral hold function can also be enabled by the user by setting PID1 Integral Hold  (14.017) = 1.

PID1 Output Scaling  (14.015) can be used to scale the output, which is limited to a range from -100.00% to 100.00% after this function. The output is then added to PID1 Feed-forwards Reference  (14.019) and is again limited to the range from -100.00% to 100.00% before being routed to the destination defined by PID1 Destination  (14.016).


Parameter14.002  PID1 Feed-forwards Reference Source
Short descriptionDefines the input source for the feed-forwards reference source for PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See PID1 Output  (14.001).


Parameter14.003  PID1 Reference Source
Short descriptionDefines the input source for the reference for PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

The reference section for the PID controllers is shown in the introduction. The pre-sleep boost control is only included in PID controller 1. The reference sections are always active even if the PID controller itself is disabled or the reference sources are not routed to valid parameters. If a reference source is not a valid parameter or is 0.000 then the value is taken as zero.

The reference PID1 Digital Reference  (14.025) is multiplied by PID1 Reference Scaling  (14.023) and then limited to +/-100.00%. The reference can then be inverted if required (PID1 Reference Invert (14.005) = 1) and then a slew rate limit is applied with PID1 Reference Slew Rate  (14.007). This limits the maximum rate of change so that a change from 0.00 to 100.00% takes the time given in PID1 Reference Slew Rate  (14.007).


Parameter14.004  PID1 Feedback Source
Short descriptionDefines the input source for the feedback for PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

Feedback

The feedback section for the PID controllers is shown in the introduction. The feedback sections are always active even if the PID controller itself is disabled or the feedback sources are not routed to valid parameters. If a reference source is not a valid parameter or is 0.000 then the value is taken as zero.

The feedback is the sum of the feedback source and the PID1 Digital Feedback  (14.026). The result is multiplied by PID1 Feedback Scaling  (14.024) and then limited to +/-100.00%. The feedback can be inverted if required (PID1 Feedback Invert  (14.006) = 1).


Parameter14.005  PID1 Reference Invert
Short descriptionSet to 1 to invert PID1 reference
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See PID1 Reference Source (14.003).


Parameter14.006  PID1 Feedback Invert
Short descriptionSet to 1 to invert the PID1 feedback
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See PID1 Feedback Source  (14.004).


Parameter14.007  PID1 Reference Slew Rate
Short descriptionDefines the rate in change of output for PID1
ModeRFC‑A
Minimum0.0Maximum3200.0
Default0.0Unitss
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places1
CodingRW

See PID1 Reference Source (14.003).


Parameter14.008  PID1 Enable
Short descriptionEnables the use of PID1
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See PID1 Output  (14.001).


Parameter14.009  PID1 Enable Source 1
Short descriptionDefines the input source for enabling PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See PID1 Output  (14.001).


Parameter14.010  PID1 Proportional Gain
Short descriptionDefines the Kp gain used for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Output  (14.001).


Parameter14.011  PID1 Integral Gain
Short descriptionDefines the Ki gain used for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default0.500Units 
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Output  (14.001).


Parameter14.012  PID1 Differential Gain
Short descriptionDefines the Kd gain used for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default0.000Units 
Type16 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Output  (14.001).


Parameter14.013  PID1 Output Upper Limit
Short descriptionDefines the maximum value of the output for PID1
ModeRFC‑A
Minimum0.00Maximum100.00
Default100.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See PID1 Output  (14.001).


Parameter14.014  PID1 Output Lower Limit
Short descriptionDefines the minimum value of the output for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default-100.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See PID1 Output  (14.001).


Parameter14.015  PID1 Output Scaling
Short descriptionDefines the scaling factor of the output for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Output  (14.001).


Parameter14.016  PID1 Destination
Short descriptionDefines the output parameter for PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, DE, PT, BU

See PID1 Output  (14.001).


Parameter14.017  PID1 Integral Hold
Short descriptionEnables the integral hold function for PID1
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit VolatileUpdate Rate4ms read
Display FormatStandardDecimal Places0
CodingRW

See PID1 Output  (14.001).


Parameter14.018  PID1 Symmetrical Limit Enable
Short descriptionEnables the symmetrical limit for PID1
ModeRFC‑A
Minimum0Maximum1
Default0Units 
Type1 Bit User SaveUpdate RateBackground read
Display FormatStandardDecimal Places0
CodingRW

See PID1 Output  (14.001).


Parameter14.019  PID1 Feed-forwards Reference
Short descriptionDisplays the value of the feed-forwards reference for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See PID1 Output  (14.001).


Parameter14.020  PID1 Reference
Short descriptionDisplays the value of the reference for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See PID1 Reference Source (14.003).


Parameter14.021  PID1 Feedback
Short descriptionDisplays the value of the feedback for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See PID1 Feedback Source  (14.004).


Parameter14.022  PID1 Error
Short descriptionDisplays the value of the error for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default Units%
Type16 Bit VolatileUpdate Rate4ms write
Display FormatStandardDecimal Places2
CodingRO, ND, NC, PT

See PID1 Output  (14.001).


Parameter14.023  PID1 Reference Scaling
Short descriptionDefines the scaling factor for the reference for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Reference Source (14.003).


Parameter14.024  PID1 Feedback Scaling
Short descriptionDefines the scaling factor of the feedback for PID1
ModeRFC‑A
Minimum0.000Maximum4.000
Default1.000Units 
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places3
CodingRW

See PID1 Feedback Source  (14.004).


Parameter14.025  PID1 Digital Reference
Short descriptionDefines the value of the digital reference for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See PID1 Reference Source (14.003).


Parameter14.026  PID1 Digital Feedback
Short descriptionDefines the value of the digital feedback for PID1
ModeRFC‑A
Minimum-100.00Maximum100.00
Default0.00Units%
Type16 Bit User SaveUpdate Rate4ms read
Display FormatStandardDecimal Places2
CodingRW

See PID1 Feedback Source  (14.004).


Parameter14.027  PID1 Enable Source 2
Short descriptionDefines the input source for enabling PID1
ModeRFC‑A
Minimum0.000Maximum59.999
Default0.000Units 
Type16 Bit User SaveUpdate RateDrive reset read
Display FormatStandardDecimal Places3
CodingRW, PT, BU

See PID1 Output  (14.001).