Siemens SIRIUS 3RK3 - Page 192

Description of the software
6.7 Functions
Modular Safety System 3RK3
190 System Manual, 10/2008, 926 2530-02 DS 02
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 Description/parameter value
Name You can enter a name for the element here.
Element number Consecutive number which is automatically assigned. You can change
the number.
Element activated 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.
General
Function output substitute
value
"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
Counter limit value CV 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.
Parameter
Reset 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".
See also
Messages for counter functions (Page 267)