Endress+Hauser ria45 - Page 28

Commissioning RIA45
28 Endress+Hauser
t
Measured value
Threshold
“off”
Hysteresis
Setpoint
Setpoint “on”
Setpoint “off”
A0010187-EN
 7 Max operating mode
Gradient
The "Gradient" operating mode is used to monitor the change in the input signal over time.
The alarm is triggered if the measured value reaches or overshoots the set value. If the
user configures a positive value, the limit value is monitored for rising gradients.
For negative values, the falling gradient is monitored.
The alarm ends if the gradient drops below the set value again. A hysteresis is not possible
for the Gradient operating mode. The alarm can be damped by means of the delay time
function (second (s) unit) to reduce the sensitivity.
M
0
M
0-m
T
m
T
0
t
T
m
! Set point
Measured value
T = Time for gradient
evaluation (Time
base in seconds)
m
Setpoint “on”
Setpoint“off”
A0010188-EN
 8 Gradient operating mode
OutBand
The limit value is violated as soon as the measured value to be checked drifts into a band
specified beforehand by minimum and maximum values. The hysteresis is located at the
outsides of the band.