Function Blocks
3.2.92 SETPT - Setpoint
SETPT function blocks can be used on a one per loop basis to
permit operator adjustment of the controller setpoint within the
loop. The on-line setpoint is adjustable, using the pulser knob,
while <loop tag>.S is the displayed variable; unless the track
command TC is high (1), at which time the setpoint will track the
TV input.
A setpoint ramping feature allows the setpoint to ramp to a
TARGET value. The start of a ramp can be initiated using a
communication command asserting input SR high (the ramp starts
on a positive transition of the SR input), or using the RAMP
ON/OFF function in the QUICKSET mode. Both ramp RATE and
ramp TIME can be set in configuration. Firmware 1.30 and higher
sets the USE RATE default to NO; earlier versions are set at YES.
Setting configuration parameter USE RATE to YES will cause the
setpoint to change at the rate setting and ignore a configured ramp
time. The RTIME or RRATE, TARGET, and PU SETPT values
can be set using the QUICKSET feature if the QUICKSET
parameter is set to YES.
The RG PTR, range pointer, parameter determines the normal operating range of the function block. If the pointer
is not configured the block will use 0.00 to 100.00. The range of the setpoint block will be limited to -10% to 110%
of the range parameter. If a range change is made the current setpoint, ramp rate, target setpoint, and power up
setpoint will be moved to be the same % values within the new range.
The setpoint block also has two inputs LU and LD that can be used to limit pulser changes in one direction. This
can be used if another function block is limiting the setpoint and it is desired not to allow the operator to adjust the
setpoint block to a value beyond the external limit.
POWER UP - The function block can be configured to power up in various conditions during a warm start. If the
PU LAST parameter is set to YES, the block will power up with the last setpoint. When SETPT does not power up
in last position or on a cold start, it will power up using the PU SETPT parameter.
LU
LD
TV
TC
.
SR
3-96
Pulser
Pulser Limit
Track Variable
SETPOINT
Track Command
Ramp Generator
TARGET Setpoint
RAMP
ON/OFF
USE
Ramp RATE
Start Ramp
BLOCK DIAGRAM
SETPOINT
SETPT
ESN = 000
R
Range
SETPOINT
TV
Track Variable
Track Command
TC
Start Ramp
SR
Limit Pulser Up
LU
Limit Pulser Down
LD
R G
P T R
RanGe PoinTeR
R
R
A
T
E
Ramp RATE (units/min)
R
T
I
M E
Ramp TIME (min)
T
A
R
G
E
T
TARGET setpoint
A
U
S E
R
T
E
USE ramp RATE
Q
U
I
C
K
S
E
T
QUICK SET setpoint values
P U
S E
T
P T
Power Up SETPoinT
P U
L
A
S
T
Power Up LAST
I
N
P
U
T
T
V
..........
INPUT TV
(H)
I
N
P
U
T
C
T
INPUT TC
..........
(H)
I
N
P
U
T
S
R
INPUT SR (H) ........
I N P U T
L
U
INPUT LU
..........
(H)
I
N
P
U
T
L
D
INPUT LD
..........
(H)
E S N
Exec. Seq. No.
(H)
Output 1
PU SETPT
Ramp RATE
Ramp TIME
UM353-1
O1
Output 1
.........
(S)
loop tag.block tag
(null)
.............. Real (10.0)
(S)
................ 0 to 3840
(0)
(S)
........................ Real (0.0)
(S)
.................. NO/YES
(NO)
(S)
. NO/YES (YES)
(S)
................... Real (0.0)
(S)
.................... NO/YES (YES)
(S)
loop tag.block tag.output
(null)
loop tag.block tag.output
(null
)
loop tag.block tag.output
(null)
loop tag.block tag.output
(null
)
loop tag.block tag.output
(null)
.................. 001 to 250
O1
.
March 2003