Bus extension for multiple masters

• US 6,484,221 B1
• Filed: 10/01/1999
• Issued: 11/19/2002
• Est. Priority Date: 10/01/1999
• Status: Expired due to Term

• Current Assignee: Storz Endoskop GmbH
• Original Assignee: Storz Endoskop GmbH
• Inventors: Bayer, Andreas, Lorinser, Andreas, Wetzel, Andre, Novak, Pavel, Irion, Klaus M.
• Primary Examiner(s): Wong, Peter
• Assistant Examiner(s): VO, TIM T
• Application Number:
  US09/411,412
• Time in Patent Office: 1,145 Days
• Field of Search: 710/107, 710/108, 710/109, 710/110, 710/111, 710/113, 710/114, 710/115, 710/116, 710/117, 710/119, 710/120, 710/121, 710/122, 710/123, 710/124, 710/309, 710/200, 710/220, 710/240, 710/241
• US Class Current: 710/200
• CPC Class Codes: G06F 13/423 with synchronous protocol

Abstract

A network bus for interconnecting a plurality of medical devices is described in which the devices are provided with modules adapted to communicate along the bus. Some of the devices are capable of assuming control over the bus with network master modules. A self-configuring capability is provided with which several network master capable medical devices automatically determine which network master is to take over control over the network bus and each individually is capable of controlling and operating the network. Each network master capable device has an extended network management module with which automatic master selection is achieved. This is done by monitoring or observing network communications for particular objects. Once such an object has been detected, a network master capable device is automatically selected to take over control on the basis of its priority. The selected network master module in turn monitors the network bus for objects indicative of another medical device which has a higher priority, while other connected master network capable medical devices continue to monitor the network bus to detect whether the current master is de-activated or fails to operate as master. The extended network module thus automatically enables another network master capable device to take over control over the network bus.

Claims

1. In a bus for a network having a communication layer to which a plurality of medical devices are coupled with modules, wherein one or several of the modules has a network master capability with which control over and communication with other medical devices can be established and wherein the network master capable medical device is characterized by an identification code and a priority code with which its status relative to other medical devices coupled to the network is determined, the improvement comprising:

first logic elements in each said network master capable devices for generating invitation objects for transmittal to other medical devices connected to the bus;

a second logic element in each said network master capable devices to detect invitation objects from other network master capable medical devices;

a detection element in each said network master capable devices to derive priority levels associated with respective network master capable medical devices;

a comparator element in each said network master capable devices for determining which network master capable device has the highest priority level; and

a switching logic element in each said network master capable devices to cease the transmittal of invitation objects from a network master capable device when an associated comparator determines that another network master capable device has a higher priority level.

2. The bus for a network as claimed in claim 1 and further including a random time delay generator element in each of said network master capable devices to randomly delay a response to a said invitation object to avoid collisions on said bus.

3. The bus for a network as claimed in claim 1 and further including a network master capable device having a speech recognition and control device located thereon for operation of the network.

4. The bus for a network as claimed in claim 2 and further including a plurality of medical devices having slave modules connected to said bus;

said slave modules generating indication objects in response to invitation objects from a network master capable device.

5. The bus for a network as claimed in claim 4 wherein said slave modules each have a random time delay generator element to randomly delay a response to a said invitation object from a network master capable device to avoid collisions on said bus.

6. The bus for a network as claimed in claim 5 wherein each of said slave modules include a logic element to derive an identification assignment from a network master capable device prior to functional operation on said bus.

7. In a communication system connected to a network to which a plurality of medical devices are coupled with modules, wherein one or several of the devices has a network master capability with which control over and communication with the medical devices can be established and wherein the network master capable medical device is characterized by an identification code and a priority code with which its status relative to other medical devices coupled to the network is determined, the improvement comprising:

first and second network master modules respectively associated with first and second medical devices, said modules producing, when in control over the network, recurring invitation objects representative of invitations to other medical devices coupled to the network to send their respective identifications, priority statuses data;

said network master modules, when not in control of said network, repeatedly sending an indication object including an identification code, and priority code to the network master module which sent the invitation object;

said network master modules further each having first logic elements for determining which network master module has a higher priority and second logic elements to cease the sending of invitation objects when a network master capable medical device having a higher priority is detected;

said network master modules further including a third logic element with which the cessation of invitation objects is detected to enable assumption of control of the network by a master capable medical device;

whereby the network master module having the highest priority is automatically selected to control the network when several network master capable medical devices are coupled to the network or one is de-coupled from the network.

8. The communication system as claimed in claim 7 and further including a random delay generator in each of said network master modules and responsive to invitation objects from an active network master capable device to delay responses thereto and avoid collisions with responses from other medical devices connected to the network.

9. A method for operating a communication network bus to which a plurality of medical devices are coupled, wherein at least a first medical device has a network master capability with which control over and communication with medical devices on the network bus can be established and wherein the first medical device is characterized by an identification code and a priority code with which its status relative to other medical devices coupled to the network bus is determined, the improvement comprising the steps of:

generating invitation objects from said first device, said invitation objects including an identification code and a priority code associated with the first device;

transmitting, in response to a said invitation object, indication objects from a second network master capable device along the network bus to provide the first device with data indicative of the identification and priority of the second network master capable device;

terminating the transmission of said invitation objects from said first device when the second network master capable device has a higher priority than said first device;

generating invitation objects from said second network master capable device when said latter device fails to detect invitation objects from said first device.

10. The method for operating a communication network bus as claimed in claim 9 and further including the step of transmitting, in response to a said invitation object, indication objects from the medical devices coupled to the network at randomly selected times to provide the first device with data indicative of the identification and priority of the medical devices with reduced collision of indication objects on the network bus.

11. The method for operating a communication network bus as claimed in claim 9 and further including the step of terminating the transmission of said invitation objects from said first device when another of the medical devices has a higher priority than said first device;

enabling said one medical device to assume control over the network bus when said first device fails to transmit invitation objects.

12. The method for operating a communication network bus as claimed in claim 9 wherein said transmitting step further includes the step of sending identification codes having a value indicative of a predetermined priority.

13. The method for operating a communication network bus as claimed in claim 9 and wherein said first network master capable device monitors the network bus for invitation objects from said second network master capable device;

and

commencing a transmission of invitation objects from said first network master capable device when invitation objects from said second network master capable device have ceased.

14. The method for operating a communication network bus as claimed in claim 9 and further including the step of deriving from the network master capable device an identification code for respective medical devices connected to the network bus prior to their operating along the network bus.