IBM System/34 Maintenance Manual page 442

30-440
Setting" the Modem Address
The modem address switch is used in multipoint
configurations only. See Figure 30-20.
Tributary Modem Addressing
On a multipoint tributary modem, set the address switch
to the same address as that of the attached DTE. The
low-order digit (right-hand digit) of the 2-digit address
must not be zero on a multipoint tributary modem. Also,
each modem DTE address must be different from other
modem DTE addresses in the network.
Multipoint Control Modem Addressing
A multipoint control modem address switch is active
only when one of the manual tests is being run (loop
transmit test).
30450 Card Switch Settings Transmit Level
United States and Canada
Over nonswitched lines, the transmit level is 0 dBm (-10
dBm for Canadian National/Canadian Pacific
Telecommunications Networks). No adjustment is
needed. Ensure that the transmit level switches are set
to the correct level.
Over switched lines, the modem transmit level is set to
o
dBm when the modem is connected to the line
through the IBM Incorporated Protective Coupler (United
States only). The IBM Incorporated Protective Coupler
automatically adjusts to the correct transmit level by
testing the program resistor installed in the wall socket
by the common carrier. No adjustment is needed.
Ensure that the transmit level switches are set to the
correct level.
In Canada, the modem is connected to the line through
a CBS Data Coupler or a similar coupler. The transmit
level must be adjusted to the value indicated on the
coupler box as shown in Figure 30-21.
Other Countries
In countries outside the U.S. and Canada, the transmit
level may change as.described by local PTT codes.
When possible, the transmit level is set when the host
unit is assembled as instructed by codes specified at
ordering time.
Setting the Transmit Level
The modem transmit level is set through transmit level
control switches. One set of switches is for
nonswitched lines, and one set of switches is" for
switched lines. Set the switches by using the
information given in Figure 30-21.
30-440 Multiline Communications Adapter 33
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