Rct_ - Repeat Cycle Timer - Siemens Moore 353 User Manual

UM353-1

3.2.83 RCT_ - Repeat Cycle Timer

RCT_ function blocks provide repeat time cycles that can
be used in logic timing operations or with PID blocks to
provide adaptive on times controlled by the PID block.
Output ET will provide the time in minutes that has
elapsed during the current cycle (ON + OFF). Output RT
is the remaining time in the current cycle and will equal the
total cycle time (ON + OFF) when the timer has not been
started.
With firmware 1.30 and higher, the ON and OFF TIME is
adjustable over the full range of the display which is
0.00000 to 999999. In earlier firmware, the minimum time
setting was 0.1. If the delay time is set to less than the scan
time of the station the delay time will equal the scan time.
Input S, asserted high (1), will cause the RCT block to start the timing cycle. Output O1 will first go high (1) for a
time set by ON TIME and then it will go low (0) for a time set by OFF TIME. It will continue to repeat this cycle
until input S is asserted low (0) which forces O1 low (0) and ends the timing cycle.
ADAPTIVE ON TIME - this feature is active only when input AT is configured. It has a valid range of 0.0 to 1.0
and there are two separate modes of adaptive on time depending on the configuration of the OFF TIME parameter.
•
OFF TIME = 0.0 - The time cycle will remain fixed and equal to the value of ON TIME. The output will be
high for a period equal to ON TIME x AT.
•
OFF TIME > 0.0 - The output will be low (0) for a period equal to OFF TIME and will be high for a period
equal to ON TIME x AT. The time cycle equals [(ON TIME x AT) + OFF TIME].
POWER UP - With the PU LAST parameter set to YES, during a hot or warm power up the block will initialize the
input/output states and elapsed time at the last values. During a cold start, they will be set to 0. With PU LAST set
to NO, during a hot start the block will initialize the input/output states and elapsed time at the last values. During a
warm or cold start, they will be set to 0.
A T
A d a p t
.
T im e
S
S t a r t
March 2003
O F F T IM E > 0 . 0
O N T I M E > 0 . 0
I N p u t A T = ( n u ll)
T I M E R
O F F T IM E = 0 . 0
O N T I M E > 0 . 0
I N p u t A T = n
O N T I M E
O F F T IM E > 0 . 0
O F F T I M E
O N T I M E > 0 . 0
I N p u t A T = n
S T A R T
B L O C K D IA G R A M
REPEAT CYCLE TIMER
RCT_ ESN = 000
Start S
REPEAT CYCLE TIMER
Adapt Time AT
O F F T I M E
OFF TIME minutes
O N T I M E
ON TIME minutes
P U L A S T
Power Up LAST
I N P U T S
INPUT S ............
(H)
N P U T T
I A
INPUT AT ..........
(H)
E S N
Exec. Seq. No.
(H)
C Y C L E O u t p u t 1
O N + O F F
O N O F F O N O F F
C Y C L E O u t p u t 1
O N
n O N O N - n O N n O N O N - n O N
O u t p u t 1
C Y C L E
n O N + O F F
n O N O F F n O N O F F
O u t p u t 1
Function Blocks
ET
Elapsed Time
RT
Remaining Time
O1
Output 1
..................... Real (0.0)
(S)
....................... Real (0.0)
(S)
................... NO/YES (YES)
(S)
loop tag.block tag.output (null)
loop tag.block tag.output (null)
.................. 001 to 250
E T
R T
O 1
.
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