Instructions

PSI-MODEMSHDSL/SERIAL
2-6
PHOENIX CONTACT 104275_en_c00
2.3.2 DSL connection
The device has two plug-in DSL connection terminal blocks, each with the connections (a)
and (b).
Figure 2-3 DSL connection
The modem is preset for line operation. You can switch to 4-wire operation via the PSI-
CONF configuration software.
Line operation
Figure 2-4 Line operation
• For line operation, connect DSL port A (a and b) to DSL port B (a and b) of the next mo-
dem. Connect a and b as desired.
DSL port B of the first device and DSL port A of the last device are not used.
NOTE:
Never connect DSL port A to DSL port B on the same device (DSL loop).
In order to make data transmission less susceptible to interference, we recommend using
shielded twisted pair cables.
You can use star-quad twisted cables. With these cables, use the individual wires on
the opposite side to avoid crosstalk (see Figure 2-6 on page 2-8). This should be ob-
served in particular in 4-wire operation.
When crosstalk is intensive, the data rate can drop sharply. At worst, no SHDSL connec-
tion is established between the two devices.
(a)
(b)
(a) (b)
DSL port A
DSL port B
PSI-MODEM-SHDSL/SERIAL
Ord.-No. 23 13 669
VCC
DG
RD
LINK
STAT
DSL A
TERM
RS232
PSI-MODEM-SHDSL/SERIAL
Ord.-No. 23 13 669
VCC
DG
RD
LINK
STAT
DSL A
TERM
RS232
PSI-MODEM-SHDSL/SERIAL
Ord.-No. 23 13 669
VCC
DG
RD
LINK
STAT
DSL A
TERM
RS232
11 32