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ASM 421 Technical Description
6GT2 097-3AH00-0DA2
– 15 –
RD: 03/02
6GT2 002-0DA00
ASM 421 / V.24
Subject to change without notice!
6GT2 002-0DB00
ASM 421 / RS422
6GT2 002-0DC00
ASM 421 / TTY
J31069-D0142-U001-A0-7618
2.4.4
RS422 cabling
TxD
RxD
*)
max.
length
1000 m
ASM 421
Computer
X2
1–9
SLG
b4
z4
b6
b8
z6
z8
X1
*)
E–
D–
D+
E+
b30/
z30
+5V
**)
**)
*)
The cable can be terminated on the receiving side with jumpers z4 – b4 and z8 – z6. This improves the interference immunity of
the system particularly when long cables are used (i.e., > 200 m). The jumpers may only be wired on the last ASM 421 when daisy
chain operation is used (see chapter 2.4.1).
**)
The indicated terminal resistors (R = 200 to 1000 Ohm) must be present on the computer side. These resistors can be wired on
the ASM side when short cables are used. This means jumpers z6 – z8 and b4 – z4 are omitted and 2 jumpers are added
(i.e., b4 – b6 and z6 – b8).
Example of a daisy-chain configuration (see 2.4.1)
CP
or
computer
+ E
– E
+ D
– D
.......
.......
Enable
Enable
Enable
dig.
inputs
SLG
ASM No. 1
ASM No. 2
ASM No. 4
SLG
SLG
z4
z8
z4
z8
z4
z8
z4
z8
b6
b8
b6
b8
b6
b8
b6
b8
b16
b16
b16
dig.
out–
puts
Request
Select
z16
max. 1000 m
z16
z16