IDEC MICROSmart FC6A Series Ladder Programming Manual page 399

Type
Turns ON the alarm output when (set point - alarm
value) ≤ process variable ≤ (set point + alarm value).
Turns OFF the alarm output when process variable ≥
(set point + alarm value + hysteresis).
Turns OFF the alarm output when process variable ≤
(set point - alarm value - hysteresis).
When (set point + alarm value) < process variable <
(set point + alarm value + hysteresis), the alarm
output maintains the state of the previous scan.
When (set point - alarm value - hysteresis) < process
Upper/Lower Limit
variable < (set point - alarm value), the alarm output
Range Alarm maintains the state of the previous scan.
Hysteresis
ON
OFF
Alarm action point
Turns ON the alarm output when process variable ≥
alarm value.
Turns OFF the alarm output when process variable ≤
(alarm value - hysteresis).
When (alarm value - hysteresis) < process variable <
alarm value, the alarm output maintains the state of
the previous scan.
Process High Alarm
ON
OFF
Turns ON the alarm output when process variable ≤
alarm value.
Turns OFF the alarm output when process variable ≥
(alarm value + hysteresis).
When alarm value < process variable < (alarm value
+ hysteresis), the alarm output maintains the state of
the previous scan.
Process Low Alarm
ON
OFF
Alarm action point
Turns ON the alarm output when process variable ≥
(set point + alarm value).
Turns OFF the alarm output when process variable ≤
(set point + alarm value - hysteresis).
When (set point + alarm value - hysteresis) < process
variable < (set point + alarm value), the alarm output
maintains the state of the previous scan.
The gray-colored portion is where the standby
function operates.
Upper Limit Alarm
with Standby
ON
OFF
- Alarm action point
Action
Alarm value Alarm value
Hysteresis
Set point Alarm action point
Hysteresis
Alarm action point
Hysteresis
Alarm value
Hysteresis
Set point + Alarm action point
FC6A S MICROS L
ERIES MART
Set point: 200.0°C
Alarm value: 5.0°C
Hysteresis: 2.0°C
When 195.0°C ≤ process variable ≤ 205.0°C, the alarm output is turned ON.
When process variable ≥ 207.0°C, the alarm output is turned OFF.
When process variable ≤ 193.0°C, the alarm output is turned OFF.
Alarm value: 205.0°C
Hysteresis: 2.0°C
When process variable ≥ 205.0°C, the alarm output is turned ON.
When process variable ≤ 203.0°C, the alarm output is turned OFF.
Alarm value: 195.0°C
Hysteresis: 2.0°C
When process variable ≤ 195.0°C, the alarm output is turned ON.
When process variable ≥ 197.0°C, the alarm output is turned OFF.
Set point: 200.0°C
Alarm value: 5.0°C
Hysteresis: 2.0°C
When process variable ≥ 205.0°C, the alarm output is turned ON.
When process variable ≤ 203.0°C, the alarm output is turned OFF.
P M
ADDER ROGRAMMING ANUAL
19: PID C
ONTROL
Example
5.0°C
2.0°C
ON
OFF
193.0°C 195.0°C 200.0°C
ON
OFF
203.0°C
ON
OFF
5.0°C
2.0°C
ON
OFF
200.0°C 203.0°C
FC9Y-B1726
I
NSTRUCTION
5.0°C
2.0°C
205.0°C 207.0°C
2.0°C
205.0°C
2.0°C
195.0°C 197.0°C
205.0°C
19-9