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Function Blocks
PID Function Block
270
HC900 Hybrid Control Designer Function Block Reference Guide
Revision 11
2/07
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
that encoded discrete switch inputs).
0 = No Change
1 = Manual Mode Request
2 = Auto Mode Request
4 = Local Mode Request
8 = Remote Mode Request
BCI
= Back Calculation Input (for blocks used as Cascade Primary)—See ATTENTION 2.
Outputs
OUT =
Control Output
WSP
= Working Setpoint in Engineering Units for monitoring
AL1
= Alarm 1 - Digital Signal
AL2
= Alarm 2 - Digital Signal
DIRECT
= ON = Direct; OFF = Reverse
ATI
= Autotune Indicator (ON = Autotune in Progress)
MODE
= Loop mode status (typically connected to the Mode Flags block for encoding). Value indicates
modes as follows:
0.0
RSP
AUTO
1.0
RSP
MAN
2.0
RSP Initialization Manual (See ATTENTION 1)
3.0
RSP Local Override (See ATTENTION 1)
4.0
LSP
AUTO
5.0
LSP
MAN
6.0
LSP Initialization Manual (See ATTENTION 1)
7.0
LSP Local Override (See ATTENTION 1)
BCO
- Back Calculation Output (for blocks used as Cascade Secondary)—See ATTENTION 2.