Tpsc (3Pos) Function Block - Honeywell UMC800 Reference Manual

Function Blocks

2.74 TPSC (3POS) Function Block

Description
The TPSC (3POS) label stands for Three Position Step Control operation. This block is part of the Loops
category. It looks like this graphically on the Control Builder
Function
This block combines a PID controller with 3 position step control output functions to provide motor
position control without position sensing. Allows the control of a valve or other actuator having an electric
motor driven by two digital output channels; one to move the motor upscale, the other to move it
downscale, without a feedback slidewire linked to the motor shaft.
Inputs
PV = Process Variable Analog Input value in Engineering Units
RSP = Remote Setpoint Analog Input value in Engineering Units or Percent
TRV = Output Track value in Percentage (PID Output = TRV Input when TRC = ON.)
TRC = Output Track Command [ON, OFF] (On -Enables TRV.) (Mode = Local Override)
BIAS = Remote Bias value for Ratio PID
SWI = Switch Inputs (from SWO on LPSW function block)
0 = No Change
1 = Initiate Autotuning
2 = Change Control Action
4 = Force Bumpless Transfer
8 = Switch to Tune Set 1
16 = Switch to Tune Set 2
MDRQI =External Mode request (typically connected to the MDRQO output of a MDSW function block.
0 = No Change
1 = Manual Mode Request
2 = Auto Mode Request
4 = Local Mode Request
8 = Remote Mode Request
214 Function Block Reference Guide 3/99