Electricity: conductors and insulators – Anti-inductive structures – Conductor transposition
Reexamination Certificate
1997-11-20
2001-06-26
Reichard, Dean A. (Department: 2831)
Electricity: conductors and insulators
Anti-inductive structures
Conductor transposition
C439S620040
Reexamination Certificate
active
06252163
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a connecting cable, a communication device and a communication method, particularly relates to a connecting cable in which an independent closed magnetic circuit interlinked with each signal conductor and formed by material provided with high magnetic permeability and predetermined magnetic reluctance is arranged for inhibiting crosstalk between signal conductors caused by the in-phase component of signals on two signal conductors, a communication device and a communication method.
2. Description of the Related Art
Recently, a device utilizing an interface according to the IEEE-1394-1995 high performance serial bus standard (an IEEE-1394 bus) for an interface for connecting plural information processors such as a computer and a video terminal is proposed.
FIG. 23
shows an example of an information processing system constituted by plural information processors which are respectively connected utilizing an interface according to the IEEE-1394-1995 standard (hereinafter, “IEEE-1394”).
The above information processing system is constituted by a workstation
101
, a personal computer
102
, a hard disk
103
, a printer
104
, a scanner
105
, an electronic camera
106
and a compact disc (CD)-ROM drive
107
respectively provided with an interface according to the IEEE-1394 standard.
The workstation
101
to the scanner
105
are respectively connected in a daisy chain mode via 1394 cables
111
-
1
to
111
-
4
according to the IEEE-1394 standard, and the electronic camera
106
and the CD-ROM drive
107
are respectively connected to the workstation
101
in a tree structure mode via 1394 cables
111
-
5
and
111
-
6
.
FIG. 24
shows an example in which predetermined two devices
141
A and
141
B of the above workstation
101
to the CD-ROM drive
107
are connected.
The 1394 cable
111
is a cable according to the IEEE-1394 standard provided with two pairs of twisted pair signal conductors
12
and
13
(further provided with two power lines not shown in the case of a 6-pin cable) and provided with a 4- or 6-pin plug
125
-
1
or
125
-
2
at each end.
FIG. 25
shows an example (in the case of a 6-pin cable) of the section of the 1394 cable
111
. As shown in
FIG. 25
, signal conductor shields
17
-
1
and
17
-
2
are respectively provided to each signal conductor
12
or
13
in the 1394 cable
111
and a whole cable shield
18
is provided outside the signal conductors
12
and
13
and the power lines
11
-
1
and
11
-
2
.
The devices
141
A and
141
B shown in
FIG. 24
are respectively provided with twisted pair A (TPA) interfaces
151
A and
151
B and twisted pair B (TPB) interfaces
152
A and
152
B respectively which are a part of an IEEE-1394 interface.
The TPA interfaces
151
A and
151
B and the TPB interfaces
152
A and
152
B respectively send/receive a signal between the two devices
141
A and
141
B and also respectively send/receive the arbitration information of cables determined in the IEEE-1394 standard and supplied from a predetermined device.
Further, the TPB interfaces
152
A and
152
B respectively supply a d.c. signal of voltage corresponding to any of plural types of maximum transfer rates determined in the IEEE-1394 standard to the TPA interfaces
151
B and
151
A of each connected device.
FIG. 26
shows an example of the electric constitution of each TPA interface
151
A and
151
B.
After a driver
161
amplifies a strobe pulse (Strb_Tx) corresponding to transmitted data when a strobe enabling signal (Strb_Enable) is supplied, the driver sends the amplified strobe pulse as a TPA signal via one of the two conductors of the signal conductor
12
or
13
and sends a signal generated by inverting a TPA signal as a TPA* signal via the other conductor of the same signal conductor.
For example, the driver
161
of the TPA interface
151
A in the device
141
A shown in
FIG. 24
sends a TPA signal and a TPA* signal via the signal conductor
12
.
An interface according to the IEEE-1394 standard adopts a DS linking system for encoding in data transmission. In the DS linking system, as shown in
FIG. 27
, predetermined data is transmitted on one signal conductor and a strobe pulse generated to change the value of the data when it is unchanged is transmitted on the other signal conductor. A clock pulse can be obtained by calculating the exclusive-OR of data and a strobe pulse.
A receiver
162
operates difference between signals transmitted via the two conductors of the signal conductor
12
or
13
and after the receiver amplifies the operated result, it outputs the amplified operated result as received data.
Arbitration comparators
163
-
1
and
163
-
2
respectively operate difference between signals corresponding to arbitration information and transmitted via the two conductors of the signal conductor as data, respectively judge whether a value showing the operated result is larger than a predetermined threshold value or not and respectively output a value corresponding to the judgement as received arbitration information.
A buffer
164
supplies predetermined reference voltage TpBias to a comparator
165
.
The comparator
165
is provided with plural comparing sections not shown, compares the voltage value of a d.c. signal corresponding to the maximum transfer rate transmitted in a common mode (a mode in which a TPA signal and a TPA* signal are in phase) via the signal conductor
12
or
13
and preset reference voltage corresponding to plural maximum transfer rates (for example, 400 Mbps, 200 Mbps and 100 Mbps), and outputs the result of the comparison (the information of the maximum transfer rate of the connected device).
FIG. 28
shows an example of the electric constitution of the TPB interfaces
152
A and
152
B.
After a driver
171
amplifies a data signal (Data_Tx) to be transmitted when a data enabling signal (Data_Enable) is supplied, the driver sends the amplified data signal as a TPB signal via one of the two conductors the signal conductor
12
or
13
and also sends a signal generated by inverting a TPB signal as a TPB* signal via the other conductor of the same signal conductor.
A receiver
172
operates difference between signals transmitted via the two conductors of the signal conductor
12
or
13
and after the receiver amplifies the operated result, it outputs the amplified operated result as a received strobe pulse.
Arbitration comparators
174
-
1
and
174
-
2
respectively operate difference between signals corresponding to arbitration information and transmitted via the two conductors of the signal conductor
12
or
13
as data, respectively judge whether a value of the operated result is larger than a predetermined threshold value or not and respectively output a value corresponding to the judgement as received arbitration information.
A cable connection comparator
175
detects a voltage value varied because the cable
111
is connected and outputs the detected result.
When a signal (Speed_Tx) corresponding to the maximum transfer rate of a device in which constant current circuits
173
-
1
and
173
-
2
are built is supplied, the constant current circuits output current corresponding to the signal, generate predetermined voltage which is in phase (in a common mode) as a TPB signal and a TPB* signal and execute speed signaling processing.
Next, communication between the devices
141
A and
141
B shown in
FIG. 24
will be described.
In the devices
141
A and
141
B connected via an interface according to the IEEE-1394 standard, first when a path is reset, the respective connected devices are informed in a common mode about the maximum transfer rate of the respective devices as speed signaling processing.
At this time, the TPB interfaces
152
A and
152
B of each device similarly apply voltage corresponding the maximum transfer rate of each device to the signal conductors
12
and
13
respectively in the constant current circuits
173
-
1
and
173
-
2
and when the TPA interfaces
151
B and
151
A of the devices connected to the above eac
Fujimori Takahiro
Kusagaya Yasuo
Yoshino Kazuo
Frommer William S.
Frommer Lawrence & Haug LLP.
Nguyen Chau N.
Reichard Dean A.
Savit Glenn F.
LandOfFree
Connecting cable, communications device and communication... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Connecting cable, communications device and communication..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Connecting cable, communications device and communication... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474633