USB multi-function connecting device

A USB multi-function connecting device includes a peripheral device connector and a pair of data upstream port and data downstream port, wherein the data upstream port is to connect the USB (Universal Serious Bus) port of a computer for receiving the peripheral device control command and data transmission from the computer. The peripheral device connector is adapted to be connected to a peripheral device and to freely define the peripheral device definition that represents the peripheral device connected thereto by the control circuit in response to the peripheral device control command from the computer so as to control the peripheral device connected thereto. The data downstream port provides a connection to an identical device in a next level or a further next level so as to interconnect the USB multi-function connecting devices to provide a multiplicity of statuses for operating different peripheral devices at the same time and thus providing a seriously-connected, multi-device, multi-function and multi-purpose USB connecting device.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a USB multi-function connecting device and 
in particular to a connecting device for connecting computer peripheral 
devices for data transfer with the peripheral devices having user-defined 
and serious form connection. 
2. Related Arts 
Computers are currently used for data processing and managing and control. 
However, in the structure of the computer, besides the central processing 
unit that is used to perform calculation and instruction execution, there 
are a number of secondary devices and substructures which are mainly 
peripheral devices for data/signal input/output, such as keyboard, joy 
stick, modem, printer, scanner, card reader, bar code reader and so on. 
Each of peripheral devices has to communicate with the computer by means 
of an interface card which serves as the control and data transfer means 
of the peripheral device. The most well known interfaces for computer 
peripheral devices are RS-232 and RS-422 which are standard computer 
interfaces. Quite apparent, the interface connection is of vital 
importance for the operation of the peripheral devices. 
Conventionally, the computers or processor based controllers used in 
industrial control operation usually adapt the so called multi-port card 
mode which has to be coupled to an ISA bus in order to function properly. 
Thus, this kind of ISA bus based multi-port card has several 
disadvantages, such as: 
(1) The computer or controller has to be taken apart in order to install 
the multiport card. 
(2) the number of the multi-port cards that may be used in a computer or a 
controller have to be the power of 2, such as 2, 4, 8 and 16 so that it 
imposes a constraint on the use of the interface card and the non-used 
cards would become a waste and consume additional power. 
(3) the computer or controller has to be shut down or turned off in 
replacing or repairing a malfunctioning multi-port card which causes 
unnecessary trouble for those systems that are difficult or not allowed to 
shut down. 
(4) it has a high manufacturing cost, is hard to maintain and has a poor 
efficiency in industrial utilization. 
(5) the interface card of each of the multi-port cards may only be a single 
function interface, such as RS-232 or RS-422, and the peripheral device 
connected thereto must be fixed and cannot be changed freely, such as a 
joy stick or other fixed peripheral device; this limits the use and 
connection of the peripheral device to the computer; further it is very 
troublesome and requires more cost if it is to connect an RS-422 to an 
RS-232 interface and vice versa. 
Further, currently, connections that made based on the USB mode are done by 
means of the bus topology, such as the connection architecture shown in 
FIG. 6, wherein each HUB can only be connected in series to other HUBs in 
the upstream direction and the downstream direction. Each HUB has a number 
of options of function. Although it is free of limitation in the selection 
of the functions, it has a disadvantage that when one of the HUB breaks 
down or malfunctions, then the HUBs that are located at lower (downstream) 
levels have to be shut off for the replacement or change of the 
malfunctioning upper level HUB. This significantly influences the 
operation and efficiency of the system. Further, each USB device is not 
matured function of each HUB is fixed, meaning it cannot be modified or 
defined in accordance with the peripheral device associated therewith. 
This makes the varieties and installation of the HUBs very complicated and 
it is difficult to design the overall system based on the use of the HUBs. 
Thus, in this case, a considerable inconvenience and difficulty would be 
had in mounting and using peripheral devices or peripheral monitoring 
devices with the HUB system. 
In addition, in Taiwan patent publication No. 292369, a typical USB 
connection module is disclosed, which is, quite obviously, similar to the 
HUB system shown in FIG. 6, having a few fixed function modes to be user 
selected, namely it only has a choice between serving a joy stick or 
serving a mouse. Besides the same problem in peripheral device connection 
as that between HUBs, an even worse problem is that the function mode 
cannot be freely modified or changed in accordance with the peripheral 
device to be connected thereto and this makes the same constraint as that 
of the HUB system shown in FIG. 6 so that the system connection and the 
operation efficiency are similarly remarkably affected. 
SUMMARY OF THE INVENTION 
Thus, an object of the present invention is to provide a USB multi-function 
connecting device which comprises a peripheral device connector, a control 
circuit and a pair of data upstream port and data downstream port, wherein 
the data upstream port is to connect to the USB from a computer in order 
to receive the control signals from the computer to the peripheral device 
and to transfer data there between,the peripheral device connector is to 
connect to the peripheral device and to freely define the peripheral 
device definition associated with the peripheral device to be connected 
thereto in accordance with peripheral device control signal from the 
computer in order to control the peripheral device connected thereto and 
to connect to the data downstream port of the same series device in the 
next level or a further next level to have the connected devices to be 
defined in a condition for use with different peripheral device so that 
the USB multi-function connecting device may be freely connected to 
different peripheral device without limitation and the maintenance and/or 
repair maybe done without shutting down the computer. Further, the number 
of the connecting device may increase/decrease without constraint 
dependent upon the peripheral devices connected thereto so as to 
significantly reduce the system and equipment cost of USB peripheral 
device connection. 
Another object of the present invention is to provide a USB multi-function 
connecting device and particularly the control circuit thereof, comprising 
a USB controller, a microprocessor, a memory module, a timer, an interrupt 
controller and an asynchronous receiver/transmitter, wherein the USB 
controller is connected to the USB output circuit of a computer and the 
next level and a further next level of USBs, the memory module comprising 
an electrical erasable programmable read only memory (EEPROM) for storing 
interface control information that defines and controls the peripheral 
device so as to allow the microprocessor in response to the software 
instruction from the computer to select the interface control program for 
a particular peripheral device from the EEPROM and to control the 
asynchronous receiver/transmitter to output it through peripheral device 
connector to the peripheral device connected thereto to be used by the 
peripheral device connected thereto, wherein the peripheral device may be 
any desired device, such as modem, mouse, keyboard, digital to analog 
convertor, sensor and those applicable in the industrial control 
engineering so as to have a better industrial utilization.

DETAILED DESCRIPTION OF THE INVENTION 
With reference to the drawings and in particular to FIG. 1, the USB 
multi-function connecting device in accordance with the present invention 
comprises a control circuit 100 which includes a USB controller 10. The 
USB controller 10 is coupled to a pair of data upstream port 11 and data 
downstream port 12. The data upstream port 11 comprises an upstream D+ 
connection line and an upstream D-connection line, making use of the 
difference in voltage level to distinguish the data transmission of "0" 
and "1". One end of the D+ connection line and the D-connection line of 
the data upstream port 11 are linked to each other (as shown by phantom 
lines in FIGS. 1 and 3) in order to connect a USB output line of a 
computer. The D+ connection line and the D- connection line of the data 
downstream port 12 are respectively connected to the D+ and D- connection 
lines of the data downstream port 12 and data upstream port 11 of a next 
level and a further next level of the multi-function connecting devices in 
order to receive peripheral device control information and commands from 
the computer and a previous level of the USB multi-function connecting 
device. 
A microprocessor 20 is connected to the USB controller 10 at a data port DP 
to receive the peripheral device control command and information from the 
USB controller 10 and to control signal output. The output control is 
achieved by means of an I/O port. 
A memory module 30 is connected to a bus of the I/O port of the 
microprocessor 20, comprising a random access memory (DRAM) 31, a read 
only memory (ROM) 32 and an electrically erasable programmable read only 
memory (EEPROM) 33. The ROM 32 has firmware written therein for 
controlling peripheral devices, such as modem, printer, mouse, card 
reader, bar code reader or the like. The DRAM 31 receives and stores data 
transmitted through channels of the I/O port of the microprocessor 20 in 
the DRAM 31 for serving as a buffer which operates in a first-in-first-out 
(FIFO) fashion in handling the data so that the data may be handled later 
when the computer or the USB lines are less busy. Further, the DRAM 31 is 
also used to temporarily hold the data that is needed in executing the 
peripheral control command or software that is contained in the ROM 32. 
Further, the EEPROM 33 is used to store the peripheral control information 
of the peripheral device selected by the user, namely the control 
information and transmission parameters defined by the user, such as the 
control information of the peripheral devices of modem, joy stick, mouse, 
A/D and/or D/A convertor, printer, scanner, digitizer, card reader, bar 
code reader or the like. 
An interrupt controller 40 which may be set to be either lever trigger type 
or edge trigger type in the case of A/D convertor, D/A convertor or I/O 
peripheral devices to provide an interrupt vector signal to the 
microprocessor 20 or an asynchronous receiver/transmitter 50. 
Alternatively, a timer 60 is provided to interrupt a short interval within 
a given period of time. Within the interrupted interval, if the 
information of the A/D convertor, D/A convertor or I/O device matches the 
information set by the user, then the status or the related information of 
the D/A convertor or the A/D convertor is stored and the status signal is 
fed back to the USB controller 10 via the microprocessor 20. A connection 
will be later established by the USB controller 10 to the computer when 
the USB line that connects to the computer is idle. 
The asynchronous receiver/transmitter 50 is connected to the end of the I/O 
port of the microprocessor 20. The asynchronous receiver/transmitter 50 
may be of any suitable type, such as the so called universal asynchronous 
receiver/transmitter (UART) shown in the drawings, but not limited 
thereto. The asynchronous receiver/transmitter 50 provides a connection to 
a peripheral device 200, which may be a modem, printer, scanner, card 
reader, bar code reader or the like. These peripheral devices 200 are 
driven by means of standard RS-232 or RS-422 device. During the data 
receiving or transmitting operation of the asynchronous 
receiver/transmitter 50, when the receiving/transmitting operation is 
completed, a receiving/transmitting interrupt signal is sent to the 
interrupt controller 40 to signal the microprocessor 20 that data is to be 
received from or transmitted to the computer. The data is transmitted in a 
series fashion and if the computer or the USB circuit connecting the 
computer is busy, then the data that is to be received or transmitted is 
temporarily stored in the DRAM 31 of the memory module 30 and will be 
retrieved from the DRAM 31 and transmitted in the FIFO fashion when the 
computer or USB circuit is not busy. 
Referring to FIG. 2, which shows a control flow chart of the system control 
operation in the computer, the control flow chart comprises reading and 
obtaining the parameter settings and relationship between the USB 
multi-function connecting devices on the USB circuit, step 300; modifying 
the settings of the function of the USB multi-function connecting device, 
namely setting the control information that is used to retrieve the 
function of a desired peripheral device or a particular peripheral device 
from the EEPROM 33, step 310; adjusting the parameters of the USB 
multi-function connecting device or changing the designated peripheral 
device, namely after the microprocessor 20 reads the control information 
from the EEPROM 33, setting the related transmitting/receiving parameters, 
step 320; the microprocessor completely setting the transmitting/receiving 
parameters of the control information and storing them back to the EEPROM 
33, step 330; rebooting the computer after the software and hardware 
connection is completed and the parameters are set, namely resetting the 
particular function to function properly in order to confirm that the 
software and hardware are correct, step 340; and executing the application 
software of the peripheral device, step 350. After the execution of the 
control flow chart shown in FIG. 2, the USB connecting device in 
accordance with the present invention may then be used to cooperate with 
the peripheral device in a multi-function and multi-purpose fashion. 
With reference to FIG. 3, which shows the block circuit diagram of another 
embodiment of the USB connecting device in accordance with the present 
invention, wherein, contrary to FIG. 1, an I/O bi-directional transmission 
peripheral device 400 is connected to the end of the I/O bus of the 
microprocessor 20, such as an industrial A/D convertor, D/A convertor, 
sensor, liquid level controller. It may also take the definition and 
function setting mode operation described with reference to FIGS. 1 and 2 
to allow the I/O bi-directional transmission peripheral device 400 to have 
the effectiveness of multi-function and multi-purpose so that the USB 
connecting device of the present invention may be used to connect not only 
the regular computer peripheral devices, but also the industrial control 
system in order to increase the value and industrial utilization thereof. 
With reference to FIGS. 4a and 4b, which are perspective views of different 
embodiments of the USB connecting device in accordance with the present 
invention. A casing 500 encases the circuit of the USB connecting device 
shown in FIGS. 1 and 3. The data upstream port 11 and the data downstream 
port 12 are both arranged at the front side of the casing 500 to allow the 
data upstream port 11 and the data downstream port 12 of the USB 
connecting devices to connect to each other. A peripheral device connector 
510 is provided on the rear side of the casing 500 which is to connect the 
peripheral device 200 or I/O bi-directional transmission device 400 so 
that it may have a variety of types and may be a standard DB-25 connector, 
as shown in FIG. 4b. The casing 500 also has an electrical socket 520 
provided at a suitable position thereon for connection with an external 
power source which allows the USB connecting device encased in the casing 
500 to receive a DC current from an external adaptor or power source, if 
desired. 
Besides, it should be noted that as shown in FIGS. 4a and 4b, at least one 
rib 530 and a corresponding slot 540 are respectively provided on the top 
side and bottom side of the casing 500 for stacking over each other. 
With reference to FIG. 5 which shows an application of the USB connecting 
device in accordance with the present invention shown in FIGS. 1-4b, the 
data upstream port 11 of each of the USB connecting devices is connected 
to the data downstream port 12 of a previous level or a further previous 
level USB multi-function connecting device and the data downstream port 12 
of each of the USB multi-function connecting devices is connected to the 
data upstream port 11 of a next level or a further next level USB 
multi-function connecting device so as to form a circuit architecture of 
systematic jump connection. By means of the circuit connection shown in 
FIG. 5, the computer does not need to shut down in order to repair any 
malfunctioning USB connecting device. Further, the USB multi-function 
connecting device allows a user to freely define the peripheral device 
connected thereto via the computer so that it is more effective in 
operation. Besides, the number of the devices is not limited to be the 
power of 2 and may be determined in accordance with the number of the 
peripheral devices connected thereto. This significantly cuts down the 
cost used in connecting and controlling the peripheral device of the 
computer USB system. 
The above description is made with respect to the preferred embodiment of 
the present invention and for those skilled in the art, it is possible to 
make a variety of modifications and changes to the above-described 
specific embodiment without departing from the scope and spirit of the 
present invention. All these modifications and changes should be 
considered within the scope of the present invention as defined in the 
appended claims.