Specifications
AS-Interface slaves
Modules with special functions
Counter modules
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Siemens IK PI · 2012
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Overview
Counter module with spring-type terminals
The counter module is used to send hexadecimally coded count
values (LSB=D0, MSB=D3) to a higher-level controller. The
count value is increased by one for each valid count pulse at ter-
minal 8. Beginning at 0, the module counts up to 15 and then be-
gins again at 0. The controller adopts the current value and de-
termines the number of pulses between two host invocations
through subtraction from the previous value. The total number of
count pulses is determined by adding these differences.
For the values sent to be unambiguous, no more than 15 count
values are allowed between two host invocations or AS-Interface
master invocations at terminal 8. The maximum permissible
transmission frequency is calculated from these times:
f
TRmax
= 15 / T
max
T
max
: max. possible transmission time from the slave to the host
Another condition for the maximum frequency is the pulse
shaped required. For the counter to accept a pulse as valid, a
Low must have been applied at the input for at least 300 µs and
a High for at least 1 ms.
This results in a maximum frequency of
f
Zmax
= 1 / 1.3 ms = 769 Hz independent of the control system
(see figure).
Maximum frequency for the counter module
If the time criterion stipulated in the graphic is violated, the count
value is rejected.
The counter is active only for the reset parameter P2 (default).
The counter is deleted when P2 is set, and the incoming count
pulses are not registered until after P2 is reset again.
Note:
A customized function block is necessary or must be
programmed.
Counter module connection options
■
Selection and ordering data
N S A 0 0 0 8 4
U
I N 1
³
1 m s
³
3 0 0 s
t
Terminal 9: Sensor supply -
Terminal 8: Counter input
Terminal 7: Sensor supply +
Terminal 6: Unused
Terminal 5: Bus connection ASi -
Terminal 4: Bus connection ASi +
+
-
IN1
ASi-ASi+
ADDR
ASi
IN1
NSA0_00085
Version Order No.
3RK1 200-0CE03-0AA2
3RK1 200-0CG03-0AA2
Counter module
Width 22.5 mm
• With screw terminals 3RK1 200-0CE03-0AA2
• With spring-type terminals 3RK1 200-0CG03-0AA2
Kap_06_en.book Seite 70 Freitag, 2. September 2011 1:42 13
© Siemens AG 2011