Yokogawa Data Acquisition with PID Control CX2000 - Manual (Page 60)

1-48
IM 04L31A01-01E
Wait Operation
This function is used to pause the program operation when the PV cannot track the SP.
The program is paused to stop the change in the SP and waits for the PV to track the
SP. When the PV tracks the SP, the program operation is automatically resumed.
This function has the following two types of operation.
• Wait at the time of segment switching
• Wait within the segment
The operation is set using the wait zone, which is the deviation width used to determine
the tracking level of the PV input, and the wait time, which is the time until the wait zone
is reached. Up to 5 groups of wait zone and wait time combination can be specified.
The wait operation applies to each loop. Therefore, if the PV of any loop does not reach
the wait zone, the operation switches from run mode to wait mode. Wait operation does
not apply to loops that are in local mode or that are stopped. In cascade control, if the
primary loop is in local mode or if the secondary loop is stopped, wait operation does not
apply. If in hold mode, wait operation is not performed because hold mode has
precedence.
Wait at the Time of Segment Switching
Wait at the time of segment switching is the wait operation that is performed when the
PV has not reached the final SP before changing to the next segment. If the PV reaches
the wait zone within the wait time, the operation moves to the next segment at that point.
If the PV does not reach the wait zone within the wait time, the operation moves to the
next segment after the wait time elapses.
When the operation is switched to hold mode during wait operation, the wait time is
reset. If the PV has not reached the wait zone when the hold mode is cleared, the timer
is restarted from zero. If the remaining segment time is changed when in hold operation,
wait at the time of segment switching no longer applies, and the wait operation is reset.
• Operation when the PV reaches the wait zone within the wait time
If the PV reaches the wait zone of the final SP before the wait time elapses after the wait
operation is started, the operation switches from wait mode to run mode and transits to
the next segment.
SEG.n SEG.n + 1 n = 1 to 98
EVn EVn + 1
Wait zone
Wait zone
Timer
stopped
Wait time
PV
Transits to the next segment
(SEG.n + 1) when the wait zone
is reached.
Final SP
SP
1.11 Program Control Related Settings