System and method for networking a computer numerical control with a workstation

• US 6,144,895 A
• Filed: 11/26/1997
• Issued: 11/07/2000
• Est. Priority Date: 11/26/1997
• Status: Expired due to Term

• Current Assignee: Allen-Bradley Company (Rockwell Automation, Inc.)
• Original Assignee: Allen-Bradley Company LLC (Rockwell Automation, Inc.)
• Inventors: Govindaraj, Subbian, Schwarz, William C., Piatka, Michael, Slagter, James M.
• Primary Examiner(s): Grant, William
• Assistant Examiner(s): Marc, McDieunel, Marc, McDieunel
• Application Number:
  US08/979,128
• Time in Patent Office: 1,077 Days
• Field of Search: 700/181
• US Class Current: 700/181
• CPC Class Codes: G05B 19/4181 characterised by direct numerical control [DNC]
• CPC Class Codes: G05B 2219/34262 DDE direct data exchange, DLL dynamic library linking
• CPC Class Codes: G05B 2219/34272 Communication pc and nc, pic over file system of pc, direct access pc to nc, pic
• CPC Class Codes: G06F 9/543 User-generated data transfer, e.g. clipboards, dynamic data exchange [DDE], object linking and embedding [OLE]
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A system combines an open control interface workstation, e.g., a properly configured personal computer, with a networked computer numerical control. The personal computer and CNC are preferably linked to a local area network such as an Ethernet network. The open control interface is configured to utilize Windows DDE, or other protocol, to accomplish process-to-process communications with other DDE-compliant Windows applications. Additionally, the open control interface is designed to allow DDE-compliant Windows applications to communicate with one or more networked computer numerical controls while minimizing data flow over the network.

Claims

1. A system that combines a workstation having a central processing unit and an open control interface with a computer numerical control designed to control machine motion, comprising:

an open control interface using a process-to-process communication protocol;

a computer numerical control having at least one processor;

a machine coupled to the computer numerical control, the motion of the machine being controlled by the computer numerical control;

a network coupled between the open control interface and the computer numerical control to carry communication between the open control interface and the computer numerical control, the network being available to carry communications between additional networked devices and the open control interface being configured to convert data entered via the open control interface into a computer numerical control format such that an operator can read and write data and execute commands on the computer numerical control through the open control interface

wherein the at least one processor is configured to maintain a watchlist of data related to control of the machine and to transmit data over the network to the open control interface only when an item on the watchlist changes, thereby conserving network and personal computer central processing unit bandwidth.

2. The system as recited in claim 1, wherein the open control interface comprises a Windows-based operator interface.

3. The system as recited in claim 2, wherein the open control interface comprises a data server that provides an interface permitting the Windows-based operator interface to send and receive data from the computer numerical control.

4. The system as recited in claim 3, wherein the open control interface implements Dynamic Data Exchange (DDE) as its communication protocol for DDE-compliant Windows applications and the data server provides a DDE interface between the CNC control and DDE-compliant Windows applications.

5. The system as recited in claim 4, wherein the network comprises a local area network (LAN).

6. The system as recited in claim 4, wherein the network comprises an Ethernet network.

7. The system as recited in claim 6, further comprising at least one additional device coupled to the network and able to receive data from the open control interface and/or send data to the open control interface.

8. The system as recited in claim 1, wherein the network comprises an Ethernet network.

9. The system as recited in claim 1, wherein data is sent over the network to the computer numerical control in the form of bundled packets of data.

10. A system that combines a workstation having a central processing unit and an open control interface with a computer numerical control designed to control machine motion, comprising:

an open control interface using a process-to-process communication protocol;

a computer numerical control having at least one processor;

a machine coupled to the computer numerical control the motion of the machine being controlled by the computer numerical control;

a network coupled between the open control interface and the computer numerical control to carry communication between the open control interface and the computer numerical control, the network being available to carry communications between additional networked devices and the open control interface being configured to convert data entered via the open control interface into a computer numerical control format such that an operator can read and write data and execute commands on the computer numerical control through the open control interface,

wherein the at least one processor is configured to maintain a watchlist of data related to control of the machine and to transmit data over the network to the open control interface only when an item on the watchlist changes, thereby conserving network and personal computer central processing unit bandwidth, wherein the data on the watchlist is polled internally by the computer numerical control via the at least one processor rather than from the open control interface.

11. The system as recited in claim 10, wherein an item of data is added or removed from the watchlist pursuant to a request from the data server.

12. An open control interface utilizing a personal computer to facilitate accessing large varieties of CNC data resident on a CNC and providing commands to the CNC, comprising:

a personal computer having an operating system that is Windows based and on which a Windows-compliant application may be run;

a protocol conversion module;

an application program interface configured to establish a link for data transfer between the Windows-compliant application and the protocol conversion module; and

a network interface cooperating with the protocol conversion module to send data through a network to which the CNC is linked,

wherein the protocol conversion module interacts with the Windows-compliant application to convert data received from the Windows-compliant application into a format suitable for use by a CNC and to convert data received from the CNC into a format appropriate for the Windows-compliant application resident on the personal computer.

13. The open control interface as recited in claim 12, further comprising a computer numerical control having a processor linked to the open control interface by a network, wherein the processor is configured to maintain a watchlist of data related to control of a machine and to transmit data over the network to the protocol conversion module only when an item on the watchlist changes, thereby conserving network and personal computer central processing unit bandwidth.

14. The open control interface as recited in claim 12, wherein the network driver is an Ethernet driver coupleable to an Ethernet network.

15. The open control interface as recited in claim 12, wherein the operating system utilizes Dynamic Data Exchange (DDE) to accomplish process-to-process communication of data between the Windows-compliant application and the protocol conversion module.

16. The open control interface as recited in claim 15, wherein multiple DDE-compliant applications can access data from the protocol conversion module.

17. A method for facilitating communication between a CNC and a personal computer having a Windows-based operating system, comprising:

placing a CNC in communication with a network capable of carrying data between a plurality of devices;

placing a personal computer, having a Windows-based operating system, in communication with the network;

entering machine control related data via the personal computer;

converting the machine control related data to a format recognizable and useable by the CNC; and

transmitting the converted machine control related data over the network to the CNC.

18. The method as recited in claim 17, further comprising coupling the CNC to a machine, wherein the motion of the machine can be controlled or monitored in accordance with the machine control related data entered on the personal computer.

19. The method as recited in claim 17, further comprising:

loading DDE-compliant applications onto the personal computer and configuring a data server to provide the DDE-compliant application access to the data server via a DDE link.

20. The method as recited in claim 19, wherein the step of converting includes converting data supplied to the data server in DDE format to a format recognizable and useable by the CNC.

21. The method as recited in claim 17, further comprising coupling the CNC to a machine tool, wherein the motion of the machine tool can be controlled or monitored in accordance with the machine tool control related data entered on the personal computer.

22. A method for facilitating communication between a CNC and a personal computer having a Windows-based operating system, comprising;

placing a CNC in communication with a network capable of carrying data between a plurality of devices;

placing a personal computer having a Windows-based operating system, in communication with the network;

entering machine control related data via the personal computer;

converting the machine control related data to a format recognizable and useable by the CNC; and

transmitting the converted machine control related data over the network to the CNC, further comprising;

maintaining a watchlist of data items at the CNC;

polling the watchlist internally by the CNC; and

transmitting data over the network to the personal computer when one of the data items changes.