Simatic 505 SoftShop
9 - PID Loops
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169
conceived for use when Automatic Download has been configured as
false, but may be used for other purposes. If Automatic Download is
false, a loop is left in manual mode with its output set to Safe Output
when a tuning session has completed. When Automatic Download is true,
a loop is switched back to its previous mode and is assigned its previous
SP on completion.
Previous SP, Previous Output, Previous Gain,
Previous Reset, Previous Rate
You can use these five parameters to record the prior SP, Mn, Kc, Ti, and
Td of a loop before a SmarTune session starts. See Previous Mode for a
short discussion on why they would be configured.
Calculated Gain, Calculated Reset, Calculated Rate
You can use these three variables to record the tuning values calculated
by SmarTune. See Previous Mode for a short discussion on why they
would be configured.
Table 9-4 lists the loop tuning errors written to the Status Variable word.
Table 9-4 Status Code Bit Values
q
p
o
n
m
l
k
j
i
h
g
f
w
e
c
r
r – reserved (always 0)
c – complete (operation is complete)
e – error (error condition detected)
w – warning (warning condition detected)
f->q meanings dependent on c-e-w bits
x – irrelevant for this condition
rcew fghi jklm nopq
Description
0000 xxxx xxxx xxxx
SmarTune in progress or not active
0000 0000 0000 0000
Not active
0000 0000 0000 1000
Waiting in SmarTune queue
0000 0000 0001 0000
Waiting for Loop to enter manual
mode
0000 0000 0001 1000
Wait 1 (PV value stabilize)
0000 0000 0010 0000
Wait 2 (PV value stabilize)
0000 0000 0010 1000
Wait 3 (PV value stabilize)
0000 0000 0011 0000
Calculating Tuning Parameters
0100 0000 0000 0000
SmarTune complete with no errors or
warnings
0101 xxxx xxxx xxxx
SmarTune complete with warning(s)
0101 xxxx xxxx xx01
Data questionable, tuning may not be
reliable
0101 xxxx xxxx xx10
Data questionable, tuning is not
reliable
0101 xxxx xxx0 01xx
Sample interval too large for optimal