YME Engineering Course

I. REGULATORY CONTROL FUNCTION BLOCKS
♦ PV Overshoot
When the data status of input signal becomes invalid (BAD), the PV
overshoot function overshoots the process variable (PV), or upscale it to
scale high-limit or downscales it to scale low-limit. Select “Overshoot PV”
or “Holding PV.” The default setting is “Holding PV.” With “Holding PV,”
when the data status of process variable (PV) becomes invalid, the last
good process variable is held. Furthermore, when the input signal is not a
process input signal, the operation becomes “Holding PV” even though
“Overshoot PV” is specified.
I.3.4 ALARM
♦ Alarm Level
Designating an alarm processing level to a function block or an element,
the alarms from the function block or the element will have the designated
priority and display the designated color. The definitions for level1 to
level4 are fixed for a whole system. The alarm priorities and colors for
level5 to level16 can be defined by users.
♦ Input Open Alarm
The input open alarm check is a function that determines whether the
input values read from the field by the I/O module is out of the range of the
high and low limit input open detection setpoint values. The high-limit input
open alarm (IOP) is initiated when it is determined that the input value
exceeds the input open high detection setpoint value. Similarly, the lowlimit
input open alarm (IOP-) is initiated when the input value is below the
low-limit input open detection setpoint value. The high and low limit input
open alarm (IOP, IOP-) indicates that a failure such as severed wires in
the detection terminal or transmitter has occurred. IOP alarm detection on
both sides, high, low and no IOP alarm is selected.
♦ PV High-High/Low-Low Limit Alarm
The input high-high and low-low limit alarm check is a function that
determines whether the input process variable (PV) is out of the range of
the high-high and low-low limit alarm setpoint value (HH, LL).
YME Training Center I-12
CS3KR3-ENG 1 ST Edition Jan 2002