1.
Description
1.3
Principle of operation
Inputltimer module
6ES5400-OAAI
1
The module contains the following:
40 inputs for 24
V
DC
Four of these can be used as interrupt inputs. Interrupts can be
initiated by either the leading edge or trailing edge of the input
signal and can be disabled by removing a jumper.
Four analog timers:
Time ranges: 10 ms
-
100 ms
looms-
1
s
Is -10s
10s
-
100s
Time setting:
Coarse setting by thumbwheel switch
Fine adjustment by built-in potentiometers
Displays:
LEDs light up while the timer is running.
Accuracy of the timers:
Due to the cyclic execution of the statements, the PC does not
detect until some time later that a time has elapsed. The relative
error of a timer in relation to its delay time
tZs and the cycle time
t,,,,,
of the STEP 5 program is shown in Fig. 8.
Analog timers cannot be used for times that are shorter than the
cycle time.
At
The maximum relative error is
-
max.
=
100
[%I,
t zs tzs
The maximum absolute error is always equal to the cycle time.
In the case of programs with interrupt processing and when using
the "BEC" (block end conditionally) statements,
it
must be remem-
bered that the cycle time
tCYqLE is not constant. The maximum
relative error can always be
estrmated from
At
-
max.
=
IOO~
[%I.
tzs tzs
Digital output module
6ES5410-OM12
The module contains the following:
-
24 outputs, 24
V
DCl0.8 A; simultaneity factor 50
%
-
4 outputs, 24
V
DC12 A
Each of the 0.8
A
outputs is electronically protected against short-
circuit.
Extra-fast fuses (FF
2.51250 G) are fitted for protecting the
2
A
outputs.
The voltage induced when disconnecting inductive loads is limited
to -15
V
by internal suppression elements. With inductive loading
and rated current, the maximum switching frequency is 1
Hz.
Higher
switching frequencies are permissible with partial loading of the
outputs or if the load is predominantly resistive.
Digital output module
6ES5410-OAA41
The module contains the following:
-
16
outputs, 24
V
DC12 A; simultaneity factor 50
%
Each of the outputs is protected by an integral extra-fast fuse (FF
2.51250 G). The voltage induced when interrupting inductive loads
is limited to -15
V
by internal suppression elements. To special
order, each output can also be fitted with a freewheeling diode
which can be cut out if
it
is not needed. The circuit-breaking
characteristics (qualitative) with and without a freewheeling diode
are shown in Fig.
9.
It must be pointed out that the use of freewheeling diodes can
cause the current in the inductive load to increase again due to the
extended disconnection time. This will cause pumping of the con-
tactor contacts and therefore increased wear.
Start
T~me elapsed
Relative error: 0.. ,100
[%l
when tZs
>
tCYCLE
tzs tzs
Fig.
8
Relative error of timer
Contactor
contact
-----
t
with
I
freerherlmg d~ode
1
--3
without
)
t7
On
-----
Off
t
+
24
V
-
0.7
V
t
-
15v
L
Output module disconnected
(Q)
A-
Fig.
9
Interrupting inductive loads (qualitative characteristics)
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