U.S. patent application number 10/865580 was filed with the patent office on 2004-11-11 for glassware forming system with star network communication configuration.
Invention is credited to Leidy, D. Wayne, Redd, Matthew D., Werner, Jay E..
Application Number | 20040223509 10/865580 |
Document ID | / |
Family ID | 23967993 |
Filed Date | 2004-11-11 |
United States Patent
Application |
20040223509 |
Kind Code |
A1 |
Redd, Matthew D. ; et
al. |
November 11, 2004 |
Glassware forming system with star network communication
configuration
Abstract
A glassware forming system that includes a plurality of
electronic devices for performing operations on articles of
glassware. These devices may comprise devices for controlling the
glassware forming operation by controlling one or more operating
mechanisms of a glassware forming system, or may comprise devices
for inspecting articles of glassware for commercial variations that
may affect commercial acceptability of the glassware and call for
possible adjustment or repair of the glassware forming system. A
network interconnects the devices for intercommunication among the
devices, and includes a star network hub and conductors connecting
the hub to the plurality of devices in a star network configuration
for bidirectional communication among the devices through the hub.
The star network hub includes a hub controller for controlling
operation of the hub according to a CANbus communication protocol,
circuitry for sensing initiation of communication from one of the
devices, and circuitry for blocking transmission of such
communication to the device from which the communication is
initiated and enabling communication from the device through the
star network hub to all other devices connected to the hub.
Inventors: |
Redd, Matthew D.; (Toledo,
OH) ; Leidy, D. Wayne; (Perrysburg, OH) ;
Werner, Jay E.; (Toledo, OH) |
Correspondence
Address: |
OWENS-ILLINOIS, INC.
ONE SEAGATE, 25-LDP
TOLEDO
OH
43666
US
|
Family ID: |
23967993 |
Appl. No.: |
10/865580 |
Filed: |
June 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10865580 |
Jun 9, 2004 |
|
|
|
09495273 |
Jan 31, 2000 |
|
|
|
Current U.S.
Class: |
370/446 |
Current CPC
Class: |
C03B 9/41 20130101; Y02P
90/18 20151101; G05B 2219/45009 20130101; G05B 2219/31157 20130101;
G05B 19/4185 20130101; Y02P 90/02 20151101; G05B 2219/31136
20130101; G05B 2219/34024 20130101 |
Class at
Publication: |
370/446 |
International
Class: |
H04B 007/204; H04L
012/413 |
Claims
1. In an individual section machine glassware forming system that
includes an individual section machine with a plurality of
individual sections for forming glass gobs into articles of
glassware, a conveyor for receiving and transporting articles of
glassware from the machine, and a plurality of electronic devices
responsive to operating conditions in said system for controlling
at least one aspect of system operation, a network interconnecting
said devices for intercommunication among said devices comprising:
a star network hub and means connecting said hub to said plurality
of devices in a star network configuration for bidirectional
communication with each other among said devices through said hub,
said star network hub including: a hub controller for controlling
said bidirectional communication with each other among said devices
according to a CANbus communication protocol, means for sensing a
communication transmitted from one of said devices, and means
responsive to said sensing means and to said hub controller for
blocking transmission of communication to said one of said devices
and for enabling communication from said one of said devices
through said star network hub to all other devices connected to
said hub.
2. The system set forth in claim 1 wherein said star network hub
further includes a plurality of transceivers for connection to said
devices.
3. The system set forth in claim 1 wherein said sensing means and
said means responsive to said sensing means comprise a field
programmable gate array.
4. The system set forth in claim 1 wherein said star network hub
further includes means responsive to termination of communication
from said one of said devices for delaying enablement of
communication from other of said devices to accommodate differences
in lengths of said connecting means.
5. The system set forth in claim 1 wherein said devices comprise
means for inspecting glassware from said conveyor.
6. The system set forth in claim 1 wherein said means responsive to
said sensing means comprises a plurality of channels, one for each
of said devices, with each said channel including a gate having an
output for enabling communication from the associated device, one
input for receiving communication from the associated device, and a
second input coupled to said output through delay means for
delaying enablement of communication from said associated
device.
7. In a glassware forming system that includes a plurality of
electronic devices for performing operations on articles of
glassware, a network interconnecting said devices for
intercommunication among said devices comprising: a star network
hub and means connecting said hub to said plurality of devices in a
star network configuration for bidirectional communication among
said devices through said hub, said star network hub including: a
hub controller for controlling said bidirectional communication
among said devices with each other according to a CANbus
communication protocol, means for sensing a communication
transmitted from one of said devices, and means responsive to said
sensing means and to said hub controller for blocking transmission
of communication to said one of said devices and for enabling
communication from said one of said devices through said star
network hub to all other devices connected to said hub.
8. The system set forth in claim 7 wherein said star network hub
further includes means responsive to termination of communication
from said one of said devices for delaying enablement of
communication from other of said devices to accommodate differences
in lengths of said connecting means.
9. The system set forth in claim 7 wherein said means responsive to
said sensing means comprises a plurality of channels, one for each
of said devices, with each said channel including a gate having an
output for enabling communication from the associated device, one
input for receiving communication from the associated device, and a
second input coupled to said output through delay means for
delaying enablement of communication from said associated
device.
10. In a glassware forming system that includes a plurality of
electronic devices for performing operations on articles of
glassware, a network interconnecting said devices for
intercommunication among said devices, comprising: a star network
including a network hub connecting said plurality of devices in a
star network configuration for bidirectional communication with
each other among said devices through said hub, said star network
hub including: a hub controller for controlling said bidirectional
communication among said devices with each other according to a
CANbus communication protocol, first electronic gates for sensing a
communication transmitted from one of said devices, and second
electronic gates responsive to said first gates and to said hub
controller for blocking transmission of communication to said one
of said devices and for enabling communication from said one of
said devices through said star network hub to all other devices
connected to said hub.
11. The system set forth in claim 10 wherein said star network hub
further includes third electronic gates responsive to termination
of communication from said one of said devices for delaying
enablement of communication from other of said devices to
accommodate differences in lengths of said connecting means.
12. The system set forth in claim 10 wherein said first electronic
gates form a plurality of channels, one for each of said devices,
with each said channel including an enabling gate having an output
for enabling communication from the associated device, one input
for receiving communication from the associated device, and a
second input coupled to said output through delay gates for
delaying enablement of communication from said associated
device.
13. The system set forth in claim 12 wherein said first and second
electronic gates, including said enabling gates and said delay
gates, are part of a field programmable gate array.
14. In an individual section machine glassware forming system that
includes an individual section machine with a plurality of
individual sections for forming glass gobs into articles of
glassware, a conveyor for receiving and transporting articles of
glassware from the machine, and a plurality of electronic devices
responsive to operating conditions in said system for controlling
at least one aspect of system operation, a network interconnecting
said devices for intercommunication among said devices comprising:
a star network hub and means connecting said hub to said plurality
of devices in a star network configuration for bidirectional
communication with each other among said devices through said hub,
said star network hub including: a hub controller for controlling
said bidirectional communication with each other among said devices
according to a CANbus communication protocol, means for sensing a
communication transmitted from one of said devices, and means
responsive to said sensing means and to said hub controller for
blocking transmission of communication to said one of said devices
and for enabling communication from said one of said devices
through said star network hub to all other devices connected to
said hub, said sensing means and said means responsive to said
sensing means comprising a field programmable gate array.
15. The system set forth in claim 14 wherein said star network hub
further includes a plurality of transceivers for connection to said
devices.
16. The system set forth in claim 14 wherein said star network hub
further includes means responsive to termination of communication
from said one of said devices for delaying enablement of
communication from other of said devices to accommodate differences
in lengths of said connecting means.
Description
[0001] This application is a continuation of application Ser. No.
09/495,273 filed Jan. 31, 2000.
[0002] The present invention is directed to manufacture of
glassware such as hollow glass containers, and more particularly to
a communication system for implementing automatic control of one or
more aspects of a glassware forming system.
BACKGROUND AND SUMMARY OF THE INVENTION
[0003] The science of glass container manufacture is currently
served by the so-called individual section machine. Such machines
comprise a plurality of separate or individual manufacturing
sections, each of which includes a multiplicity of operating
mechanisms for converting hot gobs or charges of molten glass into
hollow glass containers. In general, each section includes one or
more blank molds in which a glass gob is initially formed in a
blowing or pressing operation, an invert arm for transferring each
blank or parison to a blow mold in which the container is blown to
final form, tongs for removing the containers onto a deadplate, and
a sweep-out mechanism for sweeping the containers from the
deadplate onto a conveyor. Additional mechanisms in the machine
provide for closure of mold halves, movement of baffles and blow
nozzles, control of mold cooling wind, etc. Other controllable
mechanisms control operation of the conveyor, inspection of
containers passing along the conveyor, transfer of the containers
to an annealing lehr, etc. U.S. Pat. Nos. 4,762,544, 5,580,366 and
5,624,473 illustrate systems of this character.
[0004] It is a general object of the present invention to provide a
network for interconnecting the operating devices of a glassware
manufacturing system for bidirectional communication employing a
CANbus communication protocol, in which the length of the
interconnection cables need not be identical, which exhibits
reduced noise susceptibility, and in which an operating device may
be disconnected from the communication network for replacement or
repair without interrupting communications among the remaining
devices.
[0005] A glassware forming system in accordance with one aspect of
the present invention includes a plurality of electronic devices
for performing operations on articles of glassware. These devices
may comprise devices for controlling the glassware forming
operation by controlling one or more operating mechanisms of a
glassware forming system, or may comprise devices for inspecting
articles of glassware for commercial variations that may affect
commercial acceptability of the glassware and call for possible
adjustment or repair of the glassware forming system. A network
interconnects the devices for intercommunication among the devices,
and includes a star network hub and conductors connecting the hub
to the plurality of devices in a star network configuration for
bidirectional communication among the devices through the hub. The
star network hub includes a hub controller for controlling
operation of the hub according to a CANbus communication protocol,
circuitry for sensing initiation of communication from one of the
devices, and circuitry for blocking transmission of such
communication to the device from which the communication is
initiated and enabling communication from the device through the
star network hub to all other devices connected to the hub. The
star network hub preferably also includes circuitry responsive to
termination of communication from the one device for delaying
enablement of communication from other devices to accommodate
differences in length of the interconnection conductors or
fiberoptics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The invention, together with additional objects, features
and advantages thereof, will be best understood from the following
description, the appended claims and the accompanying drawings in
which:
[0007] FIG. 1 is a schematic diagram of a portion of a glassware
manufacturing system embodying a star network communication system
in accordance with one presently preferred embodiment of the
invention;
[0008] FIG. 2 is a functional block diagram of the communication
system illustrated in FIG. 1;
[0009] FIG. 3 is a functional block diagram of the star network hub
illustrated in FIG. 2;
[0010] FIGS. 4A-4C are fragmentary schematic diagrams of the field
programmable gate array (FPGA) illustrated in FIG. 3;
[0011] FIG. 5 is a partial block diagram of a second embodiment of
the invention;
[0012] FIG. 6 is a state diagram that illustrates operation of each
channel in the embodiment of FIG. 5; and
[0013] FIG. 7 is a detailed block diagram of each channel in the
embodiment of FIG. 5.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] The disclosures of above-references U.S. Pat. Nos.
4,762,544, 5,580,366 and 5,624,473 are incorporated herein by
reference.
[0015] FIG. 1 illustrates a portion 10 of a glassware manufacturing
system in accordance with the present invention. An individual
section machine 12 manufactures articles 14 of glassware and places
the articles in sequence on an endless belt conveyor 16. The hot
glassware is transported by conveyor 16 through a sequence of
inspection stations 18a-18d, and thence to an annealing lehr for
stress relief, etc. Machine 12 may be as disclosed, for example, in
U.S. Pat. No. 4,362,544.
[0016] In accordance with the present invention illustrated in
FIGS. 1 and 2, inspection devices 18a-18d are interconnected in a
star communication configuration with a star network hub 24. In
accordance with the present invention, the star configuration in
which devices 18a-18d are connected to network hub 24 may be an
unbalanced star configuration or network, in which the lengths of
the interconnections are or may be unequal. In a presently
preferred embodiment of the invention, the devices communicate with
each other through network hub 24 employing the so-called CANbus
communication protocol, which is a high efficiency serial
communication protocol and described, for example, in ISO 11898
specifications, which are incorporated herein by reference. Devices
18a-18d are connected to network hub 24 by bidirectional
conductors, with transceivers being positioned in hub 24 and in
each of the devices in accordance, for example, with ISO
specification 11992, also incorporated herein by reference.
[0017] FIG. 3 is a functional block diagram of network hub 24. A
hub CAN controller 26 contains suitable programming for supervising
and arbitrating communications. Hub CAN controller 26 provides a
clock signal and a Hub CAN Transmit signal to a field programmable
gate array (FPGA) 28, which in turn provides a Hub CAN Receive
signal to hub CAN controller 26. FPGA 28 is connected to a
plurality of transceivers 30 for communication with devices
18a-18d, 20 through suitable connections.
[0018] FIGS. 4A-4C are schematic diagrams of circuitry contained
within FPGA 28. FPGA 28 provides the necessary logic needed to pass
one device's communication message to all other devices and to hub
CAN controller 26. When hub CAN controller 26 sends the message, it
must be sent back to itself since a transceiver is not present.
FIG. 4A shows the logic for gating messages from the various
devices to the hub CAN controller.
[0019] According to CAN protocol, the receive signal from each
device stays at a high logical level or recessive state when the
device is not sending a message. When a device begins to send a
message, the CAN Receive signal from that device will change to a
low logic level or dominant state. When no devices are sending a
message, all of the Device CAN Receive signals are at a high or
recessive state. This will cause all of the Filtered Out Device
signals to be at a low logic level, and the Combined CAN Out signal
to be at a high logic level. Thus, all inputs to AND gate 32 in
FIG. 4A are initially high, and the Hub CAN Receive output to hub
CAN controller 26 (FIG. 3) is high. The Hub CAN Transmit input to
inverter 34 and NOR gate 36 (FIG. 4C) is high, and all of the
Filtered Out Device inputs to gate 36 are low. The Combined CAN Out
output from gate 36 is thus initially high.
[0020] FIG. 4B illustrates two channels 38,40 for generating
associated Filtered Out Device signals, in this case for a device 1
(channel 38) and device N (channel 40). In both channels 38,40, the
Device CAN Receive inputs are initially high and the Combined CAN
Out inputs to OR gates 42 are initially high. Thus, as noted above,
the Filtered Out Device signals from each channel 38, 40 are
initially low, and the Device CAN Transmit outputs are initially
high. Each channel 38, 40 includes an AND gate 44 that receives a
Device CAN Receive input for the associated device through an
inverter 46, and which receives the output of OR gate 42 directly,
through a 0.1 microsecond delay 48, and through a 1.5 microsecond
latch 50 and inverter 52.
[0021] If device 1 begins sending a message (e.g., inspection
device 18a in FIGS. 1 and 2), the Device CAN Receive signal for
that device will change to a low logic level. This input to channel
38 operates through inverter 46 and gate 44 to switch the Filter
Out Device signal for device 1 to a high logic level because the
other inputs to AND gate 44 are already at a high logic level. This
switching of the Filtered Out Device signal for device 1 will cause
the Combined CAN Out signal (FIG. 4C) to change to a low logic
level. Thus, in channel 38 of FIG. 4B, the Device CAN Transmit
signal for device 1 will remain high due to the Filtered Out Device
signal for device 1. This inhibits transmission of the message from
device 1 back to device 1 since such retransmission would lock the
channel in that state. In the meantime, the Device CAN Transmit
signals for the other channels (e.g., channel 40) will change to a
low logic level since both the Filtered Out Device signals and the
Combined CAN Out signal will be at a low logic level. Thus,
communication from device 1 is enabled for transmission to devices
2-N, but is inhibited from retransmission back to device 1 by
generation of the Filtered Out Device signal in channel 38 for
device 1.
[0022] When the Device 1 CAN Receive signal later returns the high
logic level, the Filtered Out Device 1 signal (FIG. 4B) will return
to the low logic level. The Combined CAN Out signal (FIG. 4C)
changes back to the high logic level. For the devices other than
the transmitting device (device 1 in this example), the Device CAN
Transmit signals (FIG. 4B) return to the high logic level. However,
the 0.10 microsecond delay 48 and the 1.5 microsecond positive
edge-triggered latch 50 will maintain the Filtered Out Device
signal for device 1 at the low logic level for 1.5 microseconds.
The Device CAN Receive signal for each associated device 2-N will
have no effect during the 1.5 microsecond delay period that the
latches 50 are active. After this 1.5 microsecond time delay
period, the Device CAN Receive signal will be enabled to change the
Filtered Out Device signals for devices 2-N.
[0023] This latching of the Filtered Out Device signals is used to
prevent false errors from being detected during the CAN
acknowledgment bit portion of the communication messages. According
to CAN communication protocol, a transmitting device (device 1 in
the present example) sends a recessive state bit at the end of a
message calling for acknowledgment. Any other device that
successfully received the message must reply with a dominant bit,
which the transmitting device is waiting to detect. To accommodate
the possibility of different cable lengths between each device and
the network hub, the delays before each device's acknowledgment
arrives can vary. Use of latch delays 50 prevents each device from
detecting an error due to time differences with another device's
trailing edge of the acknowledge bit. In a hub implementation
employing CAN protocol at a speed of 250,000 bits per second, 4
microseconds is required to transmit one bit. Every bit is sampled
by CAN Controller 26 in each device at about 2.5 microseconds into
the bit time. The delay of 1.5 microseconds at latches 50 is
selected to ensure that bit information transmitted to the various
devices will be at the correct logic level at the time it is
sampled.
[0024] FIG. 5 is a partial block diagram of another embodiment of
the invention, which illustrates that the transceiver 30 for each
channel is connected to a corresponding transceiver in each device
18a-18c and 20. The transmitting state of each device is dependent
upon whether the dominant state is generated by that device or
another. In determining the logic for setting the output state of
the transmitter (TXn), the inherent delay in the transceiver must
be taken into consideration. When the transmitter (TXn) is put in a
dominant state, it will be up to 75 nsec. later before the receiver
(RXn) will register the change in state. This can create problems
in determining the proper state of the transmitter during these
transition periods. FIG. 6 is a state diagram for the RX signal
from the transceiver to FPGA 28, the transmit (TXn) signal from the
FPGA, and the combined receive (CRXn) signal from the other CAN
channels. There are six definable states for each channel, as
follows:
[0025] State 1--This is the normal State of the network when none
of the devices are trying to communicate. The receive input will be
in its recessive state (RXn=H), the combined receive input from all
the other devices will be recessive (CRXn=H), and the state of the
transmit line will be recessive (TXn=H).
[0026] State 2--This State has the RXn input dominant (RXn=L), the
CRXn input recessive (CRXn=H), and the transmit output recessive
(TXn=H). This State is a transitory condition that is caused by the
delays through the transceiver and the high clock speed of the
state machine. It can be entered into through three different sets
of circumstances.
[0027] State 1 to State 2--This is the most likely entry means into
State 2. The device connected to the channel in question begins
transmission (RXn goes low.) Since no other devices are
transmitting at that time, the CRXn input will be in a recessive
state. (This will change later when the dominant state of RXn is
transmitted to the other devices and returned to RXn through the
CRXn input.) Under these conditions the dominant state should not
be broadcast back to the originating device on that channel, which
would cause the network can get locked in the dominant state.
Therefore, TXn should remain recessive allowing the connected
device to control the state of the RXn input.
[0028] State 3 to State 2--This transition is a temporary condition
that can arise because of the delay in the transceiver reporting
back a change in state for its network segment (75 nsec. delay). If
during the acknowledge part of the transmission two devices
register a dominant input on the same clock cycle, both TX outputs
would be in a high state. If the CRXn input goes recessive before
the local device, the channel could momentarily be in State 2 until
the local device returns to a recessive state. This transition is
possible but not very likely to occur.
[0029] State 6 to State 2--This transition is also a temporary
condition due to transceiver delay. The controlling device has
returned to the recessive state and the local TX output has changed
to the recessive state, but the RX input has not yet registered the
change because of the delay through the transceiver.
[0030] State 3--This State is the normal State for a transmission
where the dominant state is originated from the local device. The
RXn input will be low, and the CRXn input will also be low because
the dominant state that is being transmitted to the other devices
is being reported back to their associated RX inputs. By looking at
FIG. 5, it can be seen that all but the local RX inputs are
combined to make the CRX input. Therefore, after the transceiver
delays have expired, the CRX input will also be in the dominant
state. Since the local device is initiating the dominant state, the
local TX output will remain recessive. This State can only be
entered from State 2.
[0031] State 4--While this State can only be entered from State 3,
there are two possible exits from this State. If the local device
is the only device that was transmitting the dominant state, then
the CRX input should return to the recessive state after the
transceiver delay has elapsed and return this channel to State 1.
If however, after 75 nsec. (length of transceiver delay), the CRX
input has not gone recessive, then another device is also
transmitting a dominant state and the output of the local TX should
change from recessive to dominant. If more than one channel is
transmitting a dominant state, the channel should ideally go
directly from State 3 to State 5 when the local RX input goes
recessive, but there is no direct way to distinguish between the
two possibilities (State 3 to 5 or State 3 to 4). The only way of
determining which case is currently active is by going into State 4
and seeing if the CRX input lasts more than 75 nsec. This momentary
error in output state should not create a communications problem
because it occurs at the bit transitions and the bit is not sampled
until much later in the bit time.
[0032] State 5--This is a transitory State that occurs because of
transceiver delays. It occurs when the dominant state is generated
from a device other than the local one (CRX=L). There can be as
much as 75 nsec. delay from when the TX output goes dominant to
when it is reported by the RX input. The channel will be in this
State until the receiver (RX) catches up with the transmitter (TX).
This State is entered from either State 1 or State 4, and in both
cases is only a transitional State needed to get to the final
State, which is State 6.
[0033] State 6--This State is the result of the dominant state
being generated by a device other than the local device (CRX
input). The only difference between this State and State 3 is the
condition of the TX output. Since the dominant state is externally
generated, it must be communicated to the local device by pulling
the TX output low (dominant state). The channel will stay in this
State until the CRX input goes back to the recessive state. When
the CRX input goes recessive, then the channel will transition
through State 2 on its way back to State 1. This State is entered
because of the transceiver delays.
[0034] The logic for each channel to support the state diagram in
FIG. 6 is shown in FIG. 7. It has been simplified to minimize space
required within the FPGA. The logic looks only at those States that
would cause the TX output to go low. A shift register is used to
determine the length of time the channel stays in State 4. By using
a 40 MHz clock, a three stage shift register provides the required
75 nsec. delay. If a different clock frequency is used, the number
of stages in the shift register must also be changed.
[0035] There has thus been disclosed a glassware forming system,
which employs a star network configuration for communication among
operating devices, that fully satisfies all of the objects and aims
previously set forth. Although the communication system of the
present invention has been disclosed in conjunction with a
presently preferred implementation for inspecting hot glassware
between an individual section machine and an annealing lehr (FIG.
1), other implementations are contemplated. For example, the
communication system of the present invention can be employed for
communication between and among computers for operating individual
sections of the glassware forming machine, as disclosed for example
in above-referenced noted U.S. Pat. Nos. 5,580,366 and 5,624,473.
The communication system of the present invention can also be
employed for communication among hot end and/or cold end inspection
equipment as disclosed, for example, in above-referenced U.S. Pat.
No. 4,762,544. The network hub in the preferred embodiments of the
invention employs a field programmable gate array, which is a
commercially available programmable logic device that contains an
array of hardware logic elements that are variably configurable to
process signal data. However, FPGA 28 could be replaced by an array
of standard hardware logic elements, if desired. Other
modifications and variations will readily suggest themselves to
persons of ordinary skill in the art. The invention is intended to
embrace all such modifications and variations as fall within the
spirit and broad scope of the appended claims.
* * * * *