Honeywell HC900 Reference Manual page 285

ATTENTION
1.
When a request to change from Auto to manual is received and:
− the request comes from the operator Interface, the request is ignored.
− the request comes from the Mode Switch (MDSW) function block, the request is retained
2.
BCO output is provided for applications where the block is used as a cascade secondary.
BCI input is provided for applications where the block is used as a cascade primary. When
the BCO output of a secondary loop is connected to the BCI input of a primary loop,
bumpless transfer is achieved when the secondary is switched into remote setpoint (i.e.,
cascade) mode. In addition, the primary loop is prevented from reset windup when the
secondary is de-coupled from the process. The secondary is de-coupled from the process
when it is in local setpoint mode or manual output mode or has reached a setpoint or
output limit or is integral limiting because of its BCI input. For example, see
Block properties
Double click on the function block to access the function block properties dialog box.
Dialog box structure
The PID properties dialog box is divided into 7 tab cards
GENERAL
START/RESTART
RSP
RANGE/LIMIT
TUNING
ACCUTUNE III
ALARMS
Click on the tab to access the properties for that tab.
Revision 11
2/07
and when leaving the Initialization Mode or Local Override Mode the loop will go to
manual.
HC900 Hybrid Control Designer Function Block Reference Guide
Function Blocks
PID Function Block
F igure 73.
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