Isdn Fax Installation Notes - Xerox WorkCentre Pro 423 Service Manual

2.3.2.6 ISDN Fax installation notes

ISDN supports G4 and G3 fax communication. A G4/G3 Fax can accommodate an ISDN line
directly but a G3 Fax cannot. Therefore, a G3 Fax is connected to ISDN through a terminal
adapter (hereinafter, TA) or ISDN router (hereinafter, router). If the TA or router has an S/T
point (see "Explanations of terms"), a G4/G3 Fax may be connected directly there.
G3 Fax communication through an ISDN line is called ISDN-G3.
The following sections explain common terms about fax communication (G4 and G3) through
an ISDN line, fax and TA/router parameter setting notes, and troubleshooting in transmission
and reception.
Explanations of terms
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Terminating resistor (terminator)
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ISDN cable, 10BASE-T cable, and modular jack (MJ) RJ45 and RJ11
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S/T point
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Bus wiring
Installation notes
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Several terminals on a single ISDN line (Bus connection)
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Dial-in contract line
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Using NET1500
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PBX accommodation
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G4/G3 Fax connection to S/T point of TA or router
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G3 Fax connection to analog point of TA or router
2.3.2.7 Explanations of common terms
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Terminator
NET64 requires two pieces of 100-ohm terminator on the farthest terminal (connection block).
The terminators stabilize signals on a line.
especially when the DSU-terminal line is long or several terminals are connected by bus
wiring. Each line requires a pair of terminators.
* An ISDN line uses a four-core cable consisting of two pairs of paired wires for TA/TB (signal
transmission) and RA/RB (signal reception). The terminators are connected between TA and
TB and between RA and RB.
WorkCentre Pro 423/428
Without the terminators, errors will occur
03/02
2-101
TAs or routers and ISDN terminals may have built-in terminators that are turned OFF and ON
by switches. If several terminals are connected by bus wiring, check the built-in terminators
and leave the rsistors alive only in one unit (one pair). If several pairs of terminators are alive
on a line, the combined resistance goes down and may cause errors or other functional
problems.
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ISDN cable, 10BASE-T cable, and modular jack (MJ) RJ45 and RJ11
A modular jack for an ISDN line is called RJ45. This MJ has eight pins for four wires.
Although there are eight pins, only the four pins (pins. 3 to 6) at the centre are used. The
polarities are TA (pin 3), RA (pin 4), RB (pin 5), and TB (pin 6). Paired-wire (stranded) cables
are used for wiring from DSU to MJ and between MJs. If a non-stranded cable is used for a
long distance, errors will occur.
For terminal-side wiring, note the distance from DSU. The wiring forms are point-point
connection where only one connection block or terminal is connected to a block and bus
wiring where several connection blocks or terminals are connected. The maximum distances
from DSU to the farthest terminal in the forms are as follows:
Point-point connection: 750 m
Short-distance bus connection (terminals at random intervals on a bus): 150 m
Long-distance bus connection (all terminals centralized within 50 m on a bus): 550 m
RJ45 MJ is connected to a terminal through a four-core ISDN cable. An ISDN cable has the
same MJ (MJ45) as a 10BASE-T cable for LAN. However, the cables are not compatible with
each other because their pin numbers and combinations are different from each other (see
the table below). If a 10BASE-T cable for ISDN is used, errors will occur.
cable type Paired pin number
ISDN Pin 3-6, pin 4-5
10BASE-T Pin 1-2, pin 3-6
If communication errors occur in Fax communication, check the cable continuity, all the
polarities between DSU and connection blocks, and paired wires of the cable. Checking the
paired wires may make it necessary to unsheathe the cable partially.
A small MJ for an analogue line is called RJ11. This MJ has six pins for two wires.
RJ45
Connection block
Pin 8 ... 1
6
Level 2 Troubleshooting
CHAPTER 2 TROUBLESHOOTING