Siemens 353 User Manual page 120

Function Blocks
3.2.89 TH_ - Track & Hold
TH_ function blocks can hold an initial value that will
transfer to the block output O1 on power up and it can be
used to track the TV input when input TC is high (1).
The HOLD value can be changed on line, using the pulser,
when the TH_.O1 block output is directly connected to X
or Y inputs in an ODC block. The range and resolution
used by the pulser making on line changes will be
determined by the X Range or Y Range inputs.
INITial VALue
Track Variab le
TV
HOLD value
Track Command
TC
BLOCK DIAGRAM
3.2.90 TOT_ - Totalizer
TOT_ function blocks accept a Boolean input and they
will retain a running total of the input transitions as the
block output as a real value for interconnection to other
blocks in the controller. The running total can be reset
when input R goes high (1). Input R is executed prior to
reading input S on each scan cycle.
Unconfigured inputs will be set to 0. When the
EDGETRIG parameter is set to 1, the total will
increment on each 0 to 1 transition on input S. When
the EDGETRIG parameter is set to 0, the total will
increment on each 1 to 0 transition.
The total will be retained during a WARM & HOT start
and will be initialized to 0.0 on a COLD start.
Input Signal
S
Totalizer
R
Reset
BLOCK DIAGRAM
3-90
Output 1
O1
X03134S0
E
Total
O1
TRACK & HOLD
TH_
Track Variable TV
TRACK & HOLD
Track Command TC
V A L
I I T
N
INITial VALue
I N P U T V
T
INPUT TV
(H)
I N P U T T C
INPUT TC
(H)
E S N
Exec. Seq. No.
TOT
TOT_ ESN = 000
Input S S
TOT
Input R R
I N P U T S
INPUT S ..........
(H)
I N P U T R
INPUT R ..........
(H)
D G E T R I G
EDGE TRIGGER
E S N
Exec. Seq. No.
UM353-1B
ESN = 000
O1 Output 1
........................... Real (0.0)
(S)
.......
loop tag.block tag.output (null)
.......
loop tag.block tag.output (null)
................ 001 to 250
(H)
O1 O utput 1
loop tag.block tag.output (null)
loop tag.block tag.output (null)
......... 0-NO/1-YES 1
(H)
................ 001 to 250
(H)
April 2012