Understanding Control Blocks

The block...

Function:

Dead Time (DT)

Delays the transfer of an input value to the next block in the chain for up to 255 seconds. It can store up to 60 values of incoming variables and sends values on a first in/first out basis.

Lead Lag (LL)

Lets you simulate process dynamics and includes a digital approximation of the exponential equations for lead lag. This block is useful in feed-forward strategies.

PID (PID)

Compares analog inputs to a user-defined set point and sends out incremental adjustments to bring the process variable closer to the set point.

On-Off Control (BB)

Receives analog values and outputs digital values.

Ramp (RM)

Increases or decreases values to a target value at a specified rate. You can enter the target values manually or they can be retrieved from other blocks. You can define three distinct stages for the ramp process.

Ratio/Bias (RB)

Lets you change incoming signals by adding a constant (bias) and/or by multiplying a constant (ratio) after subtracting an offset from the signal. This block uses less memory and executes faster than the Calculation block.