====== IpidReverse() ======

''IpidReverse()'' selects direct or reverse PID action.

{{:en-us_commands:reference:ipidreverse.svg?900|IpidReverse command operation flow}}

''void IpidReverse(uint8_t id, bool reverse)''

===== Commands =====

^ Command ^ Arguments ^ Return Value ^ Operation ^
| ''IpidReverse(id, reverse)'' | ''uint8_t id'' — PID loop number. Supports ''0'' ~ ''255''\\ ''bool reverse'' — ''false'': direct control, ''true'': reverse control | ''void'' | Selects direct or reverse PID action. |


===== Example =====

<code cpp>
void setup() {
  IpidSet(2, 4.0, 0.2, 0.0, 100, 0, 255);  // Set PID coefficients, calculation interval and output range.
  IpidReverse(2, true);  // Select direct or reverse PID action.
}

void loop() {
  float pv = ntcRead(4) / 10.0;  // Return the NTC 3950 10kΩ sensor temperature as an integer in 0.1°C units.
  float sv = 25.0;
  int output = (int)IpidRun(2, pv, sv);  // Calculate the PID output from the current value and setpoint.

  analogWrite(11, output);
}
</code>

===== Precautions =====

  * PID output can directly affect field equipment. Begin testing with a low output range and small gains.
  * ''IpidRun()'' retains the previous output until the ''sampleMs'' interval has elapsed. It may be called repeatedly in ''loop()''.
  * The integral term is automatically constrained by the output limits to reduce windup. Use ''IpidItermLimit()'' if additional limits are needed.
  * The derivative term is calculated from the PV change to reduce abrupt jumps caused by setpoint changes.
  * ''IpidReset()'' resets the integral term, previous PV and previous output value.
  * Use the same ''id'' for only one control loop.

===== Built-in Commands in the Same Category =====

  * [[:en-us_commands:reference:ipidset|IpidSet() View detailed description]]
  * [[:en-us_commands:reference:ipidrun|IpidRun() View detailed description]]
  * [[:en-us_commands:reference:ipidreset|IpidReset() View detailed description]]
  * [[:en-us_commands:reference:ipiditermlimit|IpidItermLimit() View detailed description]]
  * [[:en-us_commands:reference:ipidoutput|IpidOutput() View detailed description]]

[[:en-us_commands:builtin|← Built-in Command List]]