PCC-IV Instruction Manual (rev. 0.1)
Page 3-3
Section 3
-
Operation
The operation of the four soft-buttons and six configurable lights, shown in Figure 1, changes depending on the
blockware (i.e., control logic) that has been loaded into the memory of the PCC-IV. Throughout this Section, the
words: “Typically”, “Optionally”, “Configurable”, and “User defined” will be used to indicate that the operation of a
soft-button or display may in fact vary from that described in the examples given in this section.
Front Panel Displays and Soft-buttons
RUN Light
The green
RUN
light indicates the health of the hardware and indicates if the Blockware is being over-ridden (i.e.
FORCED or Service Manual (S/M)) or has errors.
The
RUN
light should be ON continuously.
If the RUN light is blinking or off, the PCC-IV blockware is not operating properly. A technician should be
called immediately to determine the cause of the problem.
It is normal for a technician to purposely put the
PCC-IV into either Service Manual (S/M) or FORCE mode during various maintenance procedures. However, the
PCC-IV should not be in S/M or FORCE mode during normal operation. See Section 4 for details on S/M and
FORCE modes.
The RUN light indicates Normal, Forced, or S/M Mode
Green RUN Light ON / OFF Cycle
Operating Mode
ON Continuous
Normal
Flashing
– Blinks OFF once every second
Forced Block(s)
Flashing
– Blinks ON twice every second
Service Manual
OFF Continuous
Not Operating
Note: S/M Mode RUN light indication takes priority over FORCED Mode
indication when both S/M and FORCED Modes are active.
PV Bargraph
Typically, this bargraph provides a graphical display of the
P
rocess
V
ariable (PV) over a range of from 0-100%.
“Process Variable” is control system slang for: “that specific system condition that the PCC-IV is trying to control.”
Put another way, if the PCC-IV is modulating a steam valve to control the burner fuel oil temperature, then the oil
temperature is the Process Variable (PV). If the PCC-IV is a boiler feedwater controller, the boiler drum water level
is the PV.
However, the blockware designer is free to use this bargraph to display any other variable.
SP Arrow
Typically, the PV bargraph has an arrow that provides a graphical display of the
S
et
P
oint (SP) over a range of from
0-
100%. “Setpoint” is control system slang for: “that specific value at which the PCC-IV should maintain the Process
Variable”.
Put another way, if the PCC-IV is modulating a steam valve to control the burner fuel oil temperature, then as noted
above the oil temperature is the PV (that is, Process Variable). If you want to keep the oil temperature at a constant
220 deg. F, then the Setpoint would be 220 deg. F.
Typically, since the bargraph is setup to display PV and SP simultaneously, both the bargraph and arrow will be at
the same height, when the PCC-IV is in AUTO and the controller is maintaining the desired setpoint.
However, the blockware designer is free to use this arrow to display any other variable.
OUT Bargraph
Typically, this bargraph provides a graphical display of the
OUT
put of the PCC-IV over a range of from 0-100%.
“Output” is control system slang for: “whatever the PCC-IV is changing to maintain the process at the desired
setpoint”.
