PCC-IV Instruction Manual (Rev. 0.1)
Page 6-38
Section 6
– Blockware Functions
Technical Reference
F101 [HIALM] High Alarm
Function
HIALM
compares the PV (Process Variable) Input to the
SP (Setpoint) and changes the Block Output to a "1" when PV >
SP. If
HIALM
is connected to a Panel Data Screen Tag, or directly
to an
ROUT
,
DOUT
, or
TOUT
Block, it can trigger audible/visual
alarms.
HIALM
can also be used as a trigger in Blockware to
automate a control strategy.
Example: Trigger an
ASW
to select
PID
"B" instead of
PID
"A",
when steam flow exceeds 20%. See top figure at right
Inputs 2-3, and Parameters 1-5 modify the basic behavior as
follows:
0
20
40
60
80
100
0
5
10
P
e
rc
e
n
t
Seconds
HIALM: SP=50, DB=10, DELAY=0
PV
SP
SP-DB
Output
