Yokogawa Data Acquisition with PID Control CX2000 User Manual

Page 65

1-53

IM 04L31A01-01E

Explanation of Functions

Program Operation Start Delay

You can set a delay (program start time) in starting the actual program pattern control
after carrying out the procedure for starting the program operation. The setting is
common to all loops and is valid for a single program operation. The delay cannot be
specified during program control. The control output during program control is a preset
value. Hold and advance operations cannot be performed while delay is in effect.
Selectable range of program start time: 00:00:00 to 99:59:59

Time

Delay elapses

Program operation starts

Delay

Program start operation

Specifying the Program Operation Start Segment

You can specify the start segment number that is used at the time program operation is
started. For example, this function can be used when you wish to set the program
currently in operation back to the previous segment and restart the operation. Below is
an example in which the operation is started from segment 3.

SEG4

SEG3

SEG2

SEG1

SEG5

Time

Start program operation from segment 3

Process value

Segment time of segment 3

When set to
ramp-prioritized
PV1 start

When set to time-prioritized

PV start

Current process value

When set to starting target
setpoint start

SSP

TSP1

TSP2

TSP3

TSP4

TSP5

If the program operation is started from segment 3, the program operation starts
according to the start conditions as follows.
• When set to starting SP start

The program operates using point A as the starting SP and progresses towards point C.

• When set to ramp-prioritized PV1 start

The program progresses from point B to point C.

• When set to time-prioritized PV start

Program operates from the current PV using the segment time of segment 3 and
progresses toward point C.

Hold Operation

You can hold the program progression (stop the timer) during program operation. You can
hold the program using key operation on the program operation status display, using the
external contact input, or through the communication function. While the program operation
is in hold mode, you can temporarily change the settings for the current segment. When
hold mode is cleared, the operation continues with the new settings. Temporarily means
that the changes take effect in the operation of the current segment, but the setting itself is
not changed. The settings that can be changed temporarily are indicated below.
• Change the final SP of the segment.
• Increase or decrease the remaining segment time.
However, if the segment indicated in bold is a ramp segment and the segment time ramp
setting method is used, you cannot change only the remaining segment time. If you
change the final SP, the remaining segment time changes accordingly.
In addition to releasing the hold mode, executing program RUN operation or executing
advance during hold operation also clears the hold mode.

1.11 Program Control Related Settings