S5-115F Manual
Rules Governing the Use of the S5-115F
Note
In the case of safety-related 24 V digital outputs with readback function, please note
that the holding current of the load must be greater than 1 mA.
Note
In the case of safety-related 230 V digital outputs with readback function, please note
that the holding power of the load must be greater than 5 W; for 115 V digital outputs
with readback function, the holding power must be greater than 2.5 W.
If this is not possible because the internal resistance of the load is too high, four diodes
must be connected in series in the readback lines. The diodes must be switched so that
they conduct from the load to the readback DI. At least two different diode types must
be used per branch. The recommended nominal crest working off-state voltage must
not be less than 1000 V and the nominal conducting-state current must not be less
than 1 A ( Figures 10-15, 10-17, 10-19, 10-20). You can also interrupt the readback
line with the positive-action contact of an interposing relay as an alternative to diodes
( Figure 10-21).
The following figures illustrate the difference between direct and indirect control.
Direct control
Figure 10-14.
Type 9/10 DQ, Safety-Related, Intermittent/Non-Intermittent:
Direct Control, 24 V
M
+
Subunit A
Subunit B
482 - 7LF21(M - DQ)
458 - 7LB
*
482 - 7LF31
*
DQ, M output
*
Not connected to
common pot.
R DI, P Read
482 - 7LF21
(Connected to
common pot.)
482-7LF31
(connected to
common pot.)
482 - 7LF11(P DQ)
458 - 7LB
*
482-7LF31
*
DQ, P output
*
Not connected to
common pot.
R DI, M Read
482 - 7LF11
(Connected to
common P pot.)
482-7LF31
(connected to
common pot.
24 V
EWA 4NEB 811 6148-02
10-31
