Function Blocks 
ON/OFF Function Block 
232    HC900 Hybrid Control Designer Function Block Reference Guide  Revision 11 
  2/07 
Outputs 
WSP
  = Working Setpoint in Engineering Units for monitoring 
AL1  = Alarm 1 
AL2  = Alarm 2 
DIRECT = ON = Direct; OFF = Reverse 
MODE  = Actual Mode encoded as follows: (Connect to Mode Flags block [MDFL] to encode mode 
status.) 
 0.0 RSP AUTO 
 1.0 RSP MAN 
  2.0  RSP Initialization Manual (See ATTENTION) 
  3.0  RSP Local Override (See ATTENTION) 
 4.0 LSP AUTO 
 5.0 LSP MAN 
  6.0  LSP Initialization Manual (See ATTENTION) 
  7.0  LSP Local Override (See ATTENTION) 
BCO = Back Calculation Output (for blocks used as Cascade Secondary 
 
 
ATTENTION 
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 
and when leaving the Initialization Mode or Local Override Mode the loop will go to manual. 
 
Block properties 
Double click on the function block to access the function block properties dialog box. 
Configuration parameters 
The ON/OFF properties dialog box is divided into 5 tab cards: 
GENERAL 
START/RESTART 
RSP 
RANGE/LIMIT 
ALARMS
 
Click on the tab to access the properties for that tab.