GE VersaMax PLC User Manual page 281

Words
19
Output
(Address + 18)
Signed word value representing the output of the function
block before the optional inversion. If the output polarity bit in
the Config Word is set to 0, this value equals the CV output. If
the output polarity bit is set to 1, this value equals the negative
of the CV output.
20 Derivative Term Storage
(Address + 19) Used internally for storage of intermediate values. Do not
write to this location.
21, 22 Integral Term Storage
(Address + 20. Used internally for storage of intermediate values. Do not
Address + 21) write to these locations.
23 Slew Term Storage
(Address +22) Used internally for storage of intermediate values. Do not
write to this location.
24 – 26 Previous Solution Time
(Address + 23 –
Internal storage of (time of last PID solution. Normally do not
Address + 25)
write to these locations. Some special circumstances may
justify writing to these locations.
Note: If you call the PID block in Automatic mode after a long
delay, you might want to use SVC_REQ #16 or SVC_REQ
#51 to load the current CPU elapsed time clock into Word 24
to update the last PID solution time to avoid a step change of
the integral term.
27 Integral Remainder Storage
(Address + 26) Holds remainder from integral term scaling.
28, 29
SP, PV Lower Range
(Address + 27,
SP, PV Upper Range
Address + 28)
Optional integer values in PV Counts that define high and low
display values for SP and PV. (Word 29 must be greater than
word 28.)
30 Reserved
(Address + 29) Word 30 is reserved. Do not use this location.
31, 32 Previous Derivative Term Storage
(Address + 30,
Used in calculations for derivative filter. Do not write to these
Address + 31)
locations.
33 –40 Reserved
(Address + 32 – Words 32-39 are reserved. Do not use these references.
Address + 39)
PID Built-in Function Block
For public disclosure
Parameter/Description Low Bit Range
Units
Set and Non-configurable.
maintained by
the CPU.
Set and Non-configurable.
maintained by
the CPU.
Set and Non-configurable.
maintained by
the CPU.
PV Counts -32768 to 32767
N/A Non-configurable.
Set and Non-configurable.
maintained by
the CPU.
N/A Non-configurable
GFK-1503E User Manual 281