FB_Integrator (Function Block)

Integrates the input error signal over time.

The output accumulates the input scaled by the integral gain \(K_i = 1 / T_n\), and is clamped to [Minimum, Maximum] on every cycle. Setting Tn to LTIME#0 disables integration, setting the output to zero.

Use Sync() to preset the integrator state for bumpless transfer when switching from manual to automatic mode.

Note

Set Maximum before Minimum to ensure the clamp guard applies correctly.

Use FB_init to set tTn at declaration time.

Extends: FB_SisoComponent

Properties

Maximum

Type: LREAL

Gets or sets the upper output clamp.

Internally clamped to be greater than or equal to Minimum. Set this before Minimum to ensure the guard applies correctly.

Minimum

Type: LREAL

Gets or sets the lower output clamp.

Internally clamped to be less than or equal to Maximum. Set Maximum before this property to ensure the guard applies correctly.

Tn

Type: LTIME

Gets or sets the integral action time (Tn).

This controls how aggressively the integrator responds to sustained error. A shorter value increases integral action. Setting it to LTIME#0 disables integration entirely, setting the output to zero.

Methods

FB_init

Inputs

Name	Type	Description
`bInitRetains`	`BOOL`	if TRUE, the retain variables are initialized (warm start / cold start)
`bInCopyCode`	`BOOL`	if TRUE, the instance afterwards gets moved into the copy code (online change)
`tTn`	`LTIME`	Integral action time. LTIME#0 disables integration.

Reset

Clears the integrator state and output.

Run

Advances the integrator by one time step.

Note

Must be called once per cycle on a single PLC task. If Tn is LTIME#0 the output is set to zero.

Sync

Forces the integrator state to a given value on the next Run() call.

Use this for bumpless transfer when switching from manual to automatic mode, to prevent a sudden jump in output.

Inputs

Name	Type	Description
`fValue`	`LREAL`