User manual

PID Loop Operation
(DL450 Only)
Maintenance
8--21
PID Loop Operation (DL450 only)
DL405 User Manual, 4th Edition, Rev. A
The parameters associated with each loop are listed in the following table. The
address offset is in octal, to help you locate specific parameters in a loop table. For
example, if a table begins at V2000, then the location of the reset (integral) term is
Addr+11, or V2011. Do not use the word# to calculate addresses.
Word # Address+Offset Description Format
Read on-
the-fly***
1 Addr + 0 PID Loop Mode Setting 1 bits Yes
2 Addr + 1 PID Loop Mode Setting 2 bits Yes
3 Addr + 2 Setpoint Value ( SP) word/binary Yes
4 Addr + 3 Process Variable (PV) word/binary Yes
5 Addr + 4 Bias (Integrator) Value word/binary Yes
6 Addr + 5 Control Output Value word/binary Yes
7 Addr + 6 Loop Mode and Alarm Status bits --
8 Addr + 7 Sample Rate Setting word/BCD Yes
9 Addr + 10 Gain (Proportional) Setting word/BCD Yes
10 Addr + 11 Reset (Integral) Time Setting word/BCD Yes
11 Addr + 12 Rate (Derivative) Time Setting word/BCD Yes
12 Addr + 13 PV Value, Low-low Alarm word/binary No*
13 Addr + 14 PV Va lue, Low Alarm word/binary No*
14 Addr + 15 PV Value, High Alarm word/binary No*
15 Addr + 16 PV Va lue, High-high Alarm word/binary No*
16 Addr + 17 PV Va lue, deviation alarm (YELLOW) word/binary No*
17 Addr + 20 PV Va lue, deviation alarm (RED) word/binary No*
18 Addr + 21 PV Value, rate-of-change alarm word/binary No*
19 Addr + 22 PV Value, alarm hysteresis setting word/binary No*
20 Addr + 23 PV Value, error deadband setting word/binary Yes
21 Addr + 24 reserved for future use -- --
22 Addr + 25 Loop derivative gain limiting factor setting word/BCD No**
23 Addr + 26 SP value lower limit setting word/binary Yes
24 Addr + 27 SP value upper limit setting word/binary Yes
25 Addr + 30 Control output value lower limit setting word/binary No**
26 Addr + 31 Control output value upper limit setting word/binary No**
27 Addr + 32 Remote SP Value V-Memory Address Pointer word/hex Yes
28 Addr + 33 Ramp/Soak Setting Flag bit Yes
29 Addr + 34 Ramp/Soak Programming Table Starting Address word/hex No**
30 Addr + 35 Ramp/Soak Programming Table Error Flags bits No**
31 Addr + 36 reserved for future use -- --
32 Addr + 37 reserved for future use -- --
* Read data only when alarm enable bit transitions 0 to1, ** Read data only on PLC Mode change,
*** Read on--the--fly means that the content of V--memory can be changed while the PID loop is in operation.
Loop Table
Word Definitions