Siemens Simatic RTU3030C, Руководство по эксплуатации

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Program blocks
5.7 Blocks for analog value functions
RTU303xC
282
Operating Instructions, 06/2019, C79000-G8976-C382-06
From the arrangement of the two function parameters "Limit value 1" and "Limit value 2" the
function provides:
● Limit value with hysteresis
Limit 1 ≥ Limit 2
The limit value is given a hysteresis for example to control a pump.
Two applications are possible:
–
Limit value
high
with negative hysteresis
When the input signal exceeds "Limit value 1" the output is set to 1.
When the input signal falls below "Limit value 2" the output is set to 0.
Figure 5-6 Operating diagram of an example of limit value
high
with negative hysteresis
– Limit value
low
with positive hysteresis
You can monitor the input signal for a limit value
low
with positive hysteresis if you
invert the input signal (x) using the black contact symbol (1/x).
For information on inverting, see section Parameter assignment of the blocks
(Page 251).
● Window (range monitoring)
Limit value 1" < Input signal < "Limit value 2
A range of the analog value (window) between "Limit value 1" and "Limit value 2" is
monitored.
–
Output = 1, when input signal is within the window.
Figure 5-7 Operating diagram of an example of the window function
– Output = 0, when input signal is within the window.
For this functionality you need to invert the "Output" using the black contact symbol.