Function Blocks 
DC Device Control Function Block 
Revision 11    HC900 Hybrid Control Designer Function Block Reference Guide  121 
2/07     
DC Device Control Function Block 
Description 
The DC label stands for Device Control. 
 
 
 
This block is part of the 
Auxiliary category. 
Function 
The Device Control function block is normally used to control pumps. Based on certain events listed in 
HTable 38 the device will be placed into one of six states: READY, PRESTART, STARTING, RUNNING, 
STOPPING, DISABLED, or FAILED.  The READY (off state) is the initial state of the function block. 
Each configuration is limited to a maximum of 16 Device Control function blocks. 
Forcing of outputs is NOT permitted within this block. 
Inputs 
REQ = 
(run request) when ON [Logic 1], puts the device in the Starting / Running state.  When OFF, puts 
the device in Stopping / Ready state. 
FDBK = feedback from the controlled device; ON = device has started, OFF = device has not started. 
ERR = (in) – ON when the controlled device reports a failure, causes the device control to transition to the 
FAILED state. 
 OFF = No device failure. 
^RST = an OFF to ON transition will manually reset the control when it is in the FAILED state and return 
to the READY state. 
DIS =  (disable) When OFF, the device control operates normally.  When ON, immediately transitions to 
the DISABLED state, it prevents the device from starting if in the ready state or immediately shuts-down 
the device if it is currently starting up or running state.