This table describes the output pins of the FB_PID function block:
|
Output |
Data Type |
Description |
|---|---|---|
|
q_xEn |
BOOL |
TRUE: function block enabled. FALSE: function block disabled. |
|
q_xBusy |
BOOL |
TRUE: PID is active and no internal detected error. FALSE: PID is not active or detected error. |
|
q_rPidOput |
REAL |
The output of PID controller. Range: i_stPid.rLowLim...i_stPid.rHighLim |
|
q_xMinLimActv |
BOOL |
TRUE: If PID output Less than or equal to i_stPid.rLowLim (Minimum limit). FALSE: If PID output greater than i_stPid.rLowLim (Minimum limit). |
|
q_xMaxLimActv |
BOOL |
TRUE: If PID output greater than or equal to i_stPid.rHighLim (Maximum limit). FALSE: If PID output less than i_stPid.rHighLim (Maximum limit). |
|
q_xARWActv |
BOOL |
TRUE: Anti reset windup is active. FALSE: Anti reset windup is not active. |
|
q_xErr |
BOOL |
TRUE: function block detected error FALSE: No detected error. |
|
q_uiErrId |
UNIT |
Indicates the detected error number when the detected error output is set. Range: 0, 100, 103, 104, 105, 106, 107 |
|
q_sErrMsge |
STRING |
Detected error message |
|
q_sFBstat |
STRING |
Function block status |
True to indicate the enable status of function block.
TRUE if function block is started without any detected error.
If any detected error occurs, then busy output goes low.
The FB_PID starts calculating the output each cycle, if there is no detected error.
Indicate status of anti reset windup.
If integral time is greater than zero, integral action is active.
If TRUE, then integral action is stop and integral output is held at last value.
TRUE:
oCase 1: Integral time > 0.0 and ((PID Output >=Maximum limit) and (Process error > 0.0))
oCase 2: Integral time > 0.0 and ((PID Output <=Minimum limit) and (Process error < 0.0))
TRUE indicates the detected error and PID output is set to zero.
This gives detected error number and detected error message when q_xErr is TRUE.
|
Detected Error ID |
Description |
|---|---|
|
0 |
No detected error |
|
1 |
Internal detected error |
|
20 |
Invalid cycle time |
|
114 |
Invalid limit parameter |
|
115 |
Invalid dead band limit |
|
200 |
Incorrect PID parameter |
|
201 |
Incorrect Td parameter |
|
202 |
Incorrect I window |
FB Active: Function block is active and working without detected error.
FB Detected error: Function block is active and there is a detected error.
FB Disabled: Function block is disabled.
