ARBITRATION DEVICE FOR ACCESS TO A SHARED RESOURCE

    公开(公告)号:DE3480303D1

    公开(公告)日:1989-11-30

    申请号:DE3480303

    申请日:1984-06-29

    Applicant: IBM IBM FRANCE

    Abstract: An arbitration device for enabling a common resource to be shared by a plurality of processors, all connected by a common bus and each processor having a certain access priority. When more than one processor requests access to the resource, the highest priority processor request signal is latched and access is granted while the other requesting processor's latches remain set (access not granted). If two processors request access while the resource is busy, then only the latch of the processor having the highest priority of the two will be reset when the bus becomes available, and that processor will gain access.

    MULTICHANNEL MODEM AND ITS UTILIZATION IN A PROCESS AND SYSTEM FOR TESTING A COMMUNICATION NETWORK WITH SEVERAL LEVELS

    公开(公告)号:DE3069082D1

    公开(公告)日:1984-10-04

    申请号:DE3069082

    申请日:1980-11-28

    Applicant: IBM IBM FRANCE

    Abstract: 1. A multiport modem of the type comprising several input/output interfaces (7A-7D) that may respectively receive the bits of several data sub channels, multiplexing means (42, 45-46, 56) for multiplexing together the data bits received through those of the interfaces which are active to form a single train of bits in accordance with a multiplexing configuration, and transmitter means (75) for sending said train of bits over a transmission channel, characterized in that it includes : means (36) for detecting a test request received from one of the interfaces, means (30) responsive to a test request to generate a test configuration code identifying the interface that supplied said test request, means (11) responsive to said test configuration code to cause said multiplexing means to assume a test configuration such that only that interface which received the detected test request will be active, storage means (73) for storing a test command received at the interface that received the test request, said command including an indication of the test to be performed and a link level identifier, decoder means (74) for decoding said link level identifier, and means (67, 73) for applying the received test command and the test configuration code to said transmitter means for transmission over said channel if said link level identifier indicates a link level other than that which includes the modem.

    5.
    发明专利
    未知

    公开(公告)号:DE3586758T2

    公开(公告)日:1993-04-22

    申请号:DE3586758

    申请日:1985-04-30

    Applicant: IBM

    Abstract: A DTE can control the modems attached thereto by transmitting command messages over the data path and analyzing report messages supplied by the modems in return. Each command message is identified by a specific header. A command message intended for a remote modem (34) is intercepted by the local modem (30) and reformatted so as to obtain a supervisory message that is then transmitted at the rate of one bit per baud. A command message intended for a remote multichannel modem (48) is transmitted either by a supervisory message or in the data mode of operation.

    6.
    发明专利
    未知

    公开(公告)号:DE3586758D1

    公开(公告)日:1992-11-19

    申请号:DE3586758

    申请日:1985-04-30

    Applicant: IBM

    Abstract: Data terminal equipment (10) sends commands identified by specific headers to the modems over a channel, and analyses the return messages. A command to a distant modem (34) is intercepted by the local modem (30) and its format is changed into a supervisory message with a different header, for transmission at the rate of 1 bit per baud. For a distant multichannel modem (48) the command is sent either by way of a supervisory message or in data mode. Second level modems (54,58) also may be monitored by addressed data-mode comands. commands.

    MULTIPORT MODEM AND THE USE THEREOF IN A METHOD AND A SYSTEM FOR TESTING A MULTILEVEL COMMUNICATION NETWORK

    公开(公告)号:CA1172330A

    公开(公告)日:1984-08-07

    申请号:CA389262

    申请日:1981-11-02

    Applicant: IBM

    Abstract: MULTIPORT MODEM AND THE USE THEREOF IN A METHOD AND A SYSTEM FOR TESTING A MULTILEVEL COMMUNICATION NETWORK A method of testing a communication network that comprises first and second multiport modems communicating with each other through a transmission channel. Each of said modems is provided with a number of input/output interfaces and each of the interfaces on either modem is associated with a corresponding interface on the other modem. In accordance with the method of the present invention, a test request is applied to one of the interfaces on the first multiport modem, which responds thereto by generating a test configuration code identifying that interface. This modem is then caused to assume a so-called test configuration, in which only that interface to which the test request was applied is active, and a test command comprising an indication of the test to be performed and a link level identifier is applied to that interface. If the identifier designates the link level to which the first modem belongs, this modem will control the test specified in the test command. If another link level is designated then the test command and the test configuration code will both be sent to the second multiport modem. The second modem will then decode the link level identifier and, if the link level so designated is not the one to which is pertains, will assume a test configuration such that only the interface associated with the first modem interface which received the test request will be active, and the test command will be applied to that active interface. In accordance with another aspect of the invention the test configuration code also identifies the bit rate associated with the test command. The invention also provides a test system that implements the above method. The invention further provides an improved multiport modem to be used in conjunction with the test method and system mentioned above. FR9-79-013

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