Dtm_ - Dead Time Table - Siemens 353 User Manual

UM353-1B

3.2.34 DTM_ - Dead Time Table

DTM_ function blocks provide shift registers to hold the
analog input signal A for a period of time and shift it from
register to register to provide an overall delay between
input and output as configured in parameter DEADTIME.
Input AT can be used to adapt the DEADTIME to an
external signal. The actual shift register used as the block
output will equal the whole value of input AT (e.g. 0.184 =
register 0, 1.897 = register 1).
Output MA will provide the moving average of register 0
to the output register divided by the number of registers
[e.g. output register = 50, MA = (R0+R1+R2+......+R50)/51].
Input E asserted high (1) will enable the operation of the DTM block. When this input is not configured, it will be
set high. A low (0) input will cause all registers and the outputs to equal the input A.
POWER UP - During a warm or cold start, all outputs will be initialized at 0 and all registers will be initialized to
the value of the input on the first scan.
E
A
AT
April 2012
Enable
Analog Input
n
n-1
n-2
.
.
.
.
n-48
n-49
n-50
Adaptive Time
BLOCK DIAGRAM
DEAD TIME
Analog Input A
Enable E
Adaptive Time AT
D E A D E
T I M
I N P U T A
I N P U T E
I N T A T
P U
E S N
Register 0
Register 1
. .
.
. .
.
. . .
. . .
Output 1
Register 50
Moving Average
Function Blocks
ESN = 000
DTM_
O1
Output 1
DEAD TIME
Moving Average
MA
DEAD TIME ........ 0.0 to 10000 min.
(S)
INPUT A ....... loop tag.block tag.output
(H)
INPUT E .......
loop tag.block tag.output
(H)
INPUT AT .....
(H) loop tag.block tag.output
Exec. Seq. No. .............. 001 to 250
(H)
O1
MA
.
(0.0)
(null)
(null)
(null)
3-39