Siemens SIMATIC RTU3030C Operating Instructions Manual page 225

The difference of "Input 1" minus "Input 2" is monitored for the two limit values "Limit value 1"
and "Limit value 2":
By setting different values for the function parameter (Limit value 1 > Limit value 2) a
hysteresis can be programmed.
In the table note the different behavior when "Limit value 1" is lower or higher than "Limit
value 2".
Parameters
Parameters
Input parameters
En
Input 1
Input 2
Function parameters
Limit value 1
Limit value 2
Output parameters
Output
RTU3030C
Operating Instructions, 09/2017, C79000-G8976-C382-04
Tag type / range of Description
values
Enable parameter, see section Often used parameters
(Page 198).
Analog input / bit The value of the input is processed as a minuend by the
memory block function.
Event counter / usage
meter
Analog input / bit The value of the input is processed as a subtrahend by
memory the block function.
Event counter / usage
meter
3.402823 e-38 .. Turn on limit value (absolute value)
3.402823 e+38
•
Max. 19 characters,
display of max. 4
decimal places
•
3.402823 e-38 .. Turn off limit value (absolute value)
3.402823 e+38
•
Max. 19 characters,
display of max. 4
decimal places
Digital output / bit Tag in which the value calculated by the block is output.
memory
5.7 Blocks for analog value functions
Limit value 1 ≥ Limit value 2:
When the difference of "Input 1" minus "Input 2" ex-
ceeds the value "Limit value 1", the output is set to 1.
Limit value 1 < Limit value 2
When "Limit value 1" ≤ ("Input 1" minus "Input 2") <
"Limit value 2", the output is set to 1.
Limit value 1 ≥ Limit value 2:
If the difference of "Input 1" minus "Input 2" under-
shoots the value "Limit value 2" the output is set to 0.
Programming
225