User guide

Chapter 26
PID Instruction
26–11
Error code 0036 appears in the status file (S:6) when a PID instruction
runtime error occurs. Code 0036 covers the following PID error conditions,
each of which has been assigned a unique single byte code value that appears
in the MSbyte (most significant byte or upper 8 bits) of the second word
(word 1) of the PID control block.
Error
Code
(Decimal)
Error
Code
(Hex)
Description of Error Condition or Conditions Corrective Action
4352 11H
1) Loop update time D
t
> 255, or
2) Loop update time D
t
= 0
Change loop update time D
t
to
0 < D
t
< 255
4608 12H
1) Proportional gain K
c
> 255, or
2) Proportional gain K
c
= 0
Change proportional gain K
c
to
0 < K
c
< 255
4864 13H
Integral gain (reset) T
i
> 255 Change integral gain (rate) T
i
to
0 <
T
i
< 255
5120 14H
Derivative gain (rate) T
d
> 255 Change derivative gain (rate) T
d
to
0 <
T
d
< 255
8448 21H
1) Scaled setpoint max Smax > 16383, or
2) Scaled setpoint max Smax < –16383
Change scaled setpoint max Smax to
–16383 <
Smax < 16383
8704 22H
1) Scaled setpoint min Smin > 16383, or
2) Scaled setpoint min Smin < –16383
Change scaled setpoint min Smin to
–16383 <
Smin < Smax < 16383
8960 23H
Scaled setpoint min Smin > Scaled setpoint max Smax Change scaled setpoint min Smin to
–16383 <
Smin < Smax < 16383
12544 31H
If you are using setpoint scaling and Smin >
setpoint SP > Smax, or
If you are not using setpoint scaling and 0 >
setpoint SP > 16383,
then during the initial execution of the PID loop, this error occurs
and bit 11 of word 0 of the control block is set. However, during
subsequent execution of the PID loop if an invalid loop setpoint
is entered, the PID loop continues to execute using the old
setpoint, and bit 11 of word 0 of the control block is set.
If you are using setpoint scaling, then change the
setpoint SP to Smin <
SP < Smax, or
If you are not using setpoint scaling, then change
the setpoint SP to 0 <
SP < 16383.
16640 41H Scaling Selected Scaling Deselected
1) Deadband < 0, or 1) Deadband < 0, or
2) Deadband > 2) Deadband > 16383
(Smax - Smin), or
3) Deadband > 16383
Scaling Selected Scaling Deselected
Change deadband to Change deadband to
0 <
deadband < 0 < deadband <
(Smax – Smin) < 16383
16383
20736 51H
1) Output high limit < 0, or
2) Output high limit > 100
Change output high limit to
0 <
output high limit < 100
20992 52H
1) Output low limit < 0, or
2) Output low limit > 100
Change output low limit to
0 <
output low limit < output high limit < 100
21248 53H
Output low limit > output high limit Change output low limit to
0 <
output low limit < output high limit < 100
24576 60H
PID is being entered for the second time. (PID loop was inter-
rupted by an I/O interrupt, which is then interrupted by the PID STI
interrupt.)
You have at least three PID loops in your program: One in the
main program or subroutine file, one in an I/O interrupt file, and
one in the STI subroutine file. You must alter your ladder program
and eliminate the potential nesting of PID loops.
Runtime Errors