Siemens Sirius 3RK3 System Manual page 192

Description of the software
6.7 Functions
Functional principle
● The counter value is increased by 1 with every negative edge at the "Counter input up",
except when the counter value reaches the maximum value 65535.
● The counter value is decreased by 1 with every negative edge at the "Counter input
down", except when the counter value reaches the value 0.
● The counter value remains unchanged when there is a positive edge simultaneously at
both counter inputs.
Parameters
Parameter name
General Name
Element number
Element activated
Function output substitute
value
Parameter Counter limit value CV
Reset
See also
Messages for counter functions (Page 267)
190
Description/parameter value
You can enter a name for the element here.
Consecutive number which is automatically assigned. You can change
the number.
When this parameter is active, the function is processed in the safety
logic.
When this parameter is deactivated, the set substitute value is made
available at the output Q.
"0" or "1" can be assigned to the substitute value when the element is
deactivated.
Substitute value "0" means output Q = 0
substitute value "1" means output Q = 1
Set a counter limit value which is to be monitored (between 0 and
65535):
Function output Q = "1" when the current counter value reaches this
•
limit value.
Function output Q = "0" when the current counter value falls below
•
this limit value.
You can select whether the counter value is set to "0" automatically or
manually:
Automatic
•
When the function output Q = "1", the counter value and function
output Q are set to "0" after one program cycle of the safety relay.
Manual
•
The counter value is set to "0", irrespective of the state of the
function output Q.
If the counter value is not deleted after the limit value is exceeded,
counting will continue.
Automatic with manual reset
•
When the function output Q = "1", the counter value and function
output Q are set to "0" after one program cycle of the safety relay.
The counter value can be reset to "0" when the function output Q =
"0".
Modular Safety System 3RK3
System Manual, 10/2008, 926 2530-02 DS 02