Information On The Response Of The Relay Output - Endress+Hauser Proline Prosonic Flow 93 Function Manual

Device functions Proline Prosonic Flow 93
Endress+Hauser
7.3.4

Information on the response of the relay output

General
If you have configured the relay output signal for "LIMIT-VALUE" or "FLOW DIRECTION", you can define the requisite
switching points in the ON-VALUE and OFF-VALUE functions. When the measured variable in question reaches one of
these predefined values, the relay output switches as shown in the illustrations below.
Relay output configured for "flow direction"
The value you entered in the function ON-VALUE defines the switching point for the positive and negative directions of
flow.
If, for example, the switch point you define is = 1 m
switch point to 0 if your process calls for direct switchover (no switching hysteresis). If low flow cut off is used, it is advisa-
ble to set hysteresis to a value greater than or equal to the low flow cut off rate.
-Q
a Relay energized
b Relay de-energized
Relay output configured for limit value
The relay output signal switches as soon as the measured variable undershoots or overshoots a defined switch point.
Application: Monitoring flow or process-related boundary conditions.
Measured variable
➀
= ON > SWITCH-OFF POINT (maximum safety)
➁
= ON > SWITCH-OFF POINT (minimum safety)
➂
= Relay de-energised
3
/h, the relay drops out at –1 m
-1 0 +1
b
➀ ➁
➂ ➂
7 Block OUTPUTS
3 3
/h and pulls up at +1 m /h. Set the
Q
a
t
A0001236
A0001235
99