Data relaying unit and method of transmitting data between host and client devices

A data relaying unit for connection between a host device and a plurality of client devices, said data relaying unit comprising:

• a plurality of connectors corresponding to said client devices;
• a control device which, when said host device instructs that data transmission should be performed between specific ones of said client devices, manages a schedule for the data transmission between said specific client devices;
• and
• a connection switching device which connects said connectors corresponding to said specific client devices to said control device and connects other said connector corresponding to other said client device to said host device,
• whereby data is transmitted between said specific client devices in accordance with the schedule managed by said control device, without intervention of said host device.

A data relaying unit for connection between a host device and a plurality of client devices, said data relaying unit comprising:

• a plurality of connectors corresponding to said client devices;
• a control device which, when said host device instructs that data transmission should be performed between specific ones of said client devices, manages a schedule for the data transmission between said specific client devices;
• a connection switching device which connects said connectors corresponding to said specific client devices to said control device and connects other said connector corresponding to other said client device to said host device;
• and
• a device which monitors a condition of the data transmission between said specific client devices and informs said host device of the monitored condition of the data transmission.

A data relaying unit for connection between a host device and a plurality of client devices, said data relaying unit comprising:

• a plurality of connectors corresponding to said client devices;
• a control device which, when said host device instructs that data transmission should be performed between specific ones of said client devices, manages a schedule for the data transmission between said specific client devices;
• a connection switching device which connects said connectors corresponding to said specific client devices to said control device and connects other said connector corresponding to other said client device to said host device;
• and
• a device which informs said host device of the schedule managed by said control device.

A data relaying system for connection between a host device and a plurality of client devices, said data relaying system comprising a plurality of data relaying units corresponding to a plurality of client groups each including a plurality of client devices, said host device being connected with a first one of said data relaying units, other said data relaying unit being cascaded to said first data relaying unit to be able to receive an instruction from said host device, each of said data relaying units comprising:

• a plurality of connectors for connection between said client devices in the corresponding group;
• a control device which, when said host device instructs that data transmission should be performed between specific ones of said client devices in the corresponding group, manages a schedule for the data transmission between said specific client devices;
• and
• a connection switching device which connects said connectors corresponding to said specific client devices to said control device and connects other said connector corresponding to other said client device to said host device,
• whereby data is transmitted between said specific client devices in accordance with the schedule managed by said control device, without intervention of said host device.

A method for transmitting data between a host device and a plurality of client devices under management by said host device, said method comprising the steps of:

• providing a quasi host device which manages data transmission between said client devices;
• when data transmission is to be performed between said host device and a specific one of said client devices, causing said host device to manage a schedule for the data transmission;
• when said host device instructs that data transmission is to be performed between specific ones of said client devices, activating said quasi host device to manage a schedule for the data transmission between said specific client devices;
• and
• switching connection of data transmission paths depending on whether the data transmission is to be performed between said host device and said specific client device or between said specific client devices.

A method for transmitting data between a host device and a plurality of client devices under management by said host device, said method comprising the steps of:

• when data transmission is to be performed between said host device and a specific one of said client devices, performing connection switching such that a data transmission path is formed between said host device and said specific client device;
• when data transmission is to be performed between specific ones of said client devices, performing connection switching such that a data transmission path is formed between said specific client devices without intervention of said host device;
• and
• when data transmission is to be performed between specific ones of said client devices, monitoring a condition of the data transmission and informing said host device of the monitored condition of the data transmission.

A machine-readable recording medium containing a group of instructions of a program to be executed by a computer, said program comprising the steps of:

• instructing a first mode to perform data transmission between a host device and a specific client device;
• instructing a second mode to perform data transmission between a plurality of specific client devices and when said second mode is instructed, activating a quasi-host device and causing said quasi-host device to manage a schedule for the data transmission between said specific client devices;
• performing, when first said mode is instructed, connection switching such that a data transmission path is formed between said host device and said specific client device;
• and
• performing, when said second mode is instructed, connection switching such that a data transmission path is formed between said specific client devices without intervention of said host device.

A data relaying unit for connection between a host device and a plurality of client devices, said data relaying unit comprising:

• a first input/output terminal corresponding to said host device;
• a plurality of second input/output terminals corresponding to said client devices;
• a quasi host device which, in accordance with an instruction from said host device, controls direct data transmission between said client devices;
• and
• a connection switching device which selectively connects individual ones of said second input/output terminals to either said first input/output terminal or said quasi host device, wherein in accordance with an instruction from said host device, said connection switching device connects said second input/output terminals of predetermined ones of said client devices to said quasi host device so as to permit direct data transmission between said predetermined client devices.