Encoderinterface - Siemens SIMATIC S5 IP 281 Equipment Manual

R 11192
Encoder Interface
1.4.1
X35 (counter 1 ) and X 45 (counter 2) are used to make the switch–over.
A
RS 422
input
24 V
B*
input
N*
Counter 1 Counter 2
x45
x35
x45
x35
The 5 V area and the 24 V area are free–floating. To insure that this separation is retained, the
corresponding reference potential must be circuited on pin 7 of the encoder interface depending
on the"encoder selected (-t section 2.3, selecting the reference potential).
Counter 1 Counter 2
x39 x49
x49
x39
Incorrectly inserted jumpers (e.g., S5 reference potential for 24 V encoders) can lead
to interference caused by grounding loops. In addition, potential isolation between
the 24 V encoder inputs and the S5 backplane is lost.
Status on delivery: Jumper 1–2 inserted + reference potential for 24 V encoder
L
Allocation Selected Interface
1–2 For 24 V encoder
2–3 For 5 V encoder in accordance
with RS 422
Allocation
1–2 For 24 V encoder
2–3 For 5 V encoder (RS 422)
General Function Description
Multiplexer
0
0
0
X35/x45
o
?
1 Reference
2 3
potential
1 – 13
A
B
N