Data transmission system

1 . A data transmission system configured to execute data transmission bidirectionally between two electronic devices, the data transmission system comprising:

a first unidirectional transmission path configured to allow the data transmission in a first direction from one of the two electronic devices to another one of the two electronic devices;

a second unidirectional transmission path configured to allow the data transmission between the two electronic devices in a second direction being opposite to the first direction;

a bidirectional transmission path configured to allow the data transmission between the two electronic devices in a data transmission direction set to be either the first direction or the second direction; and

at least one of (i) a circuit and (ii) a processor with a memory storing computer program code executable by the processor, the at least one of the circuit and the processor configured to cause the data transmission system to:

allow a user to set the data transmission direction for the bidirectional transmission path in advance,

wherein

the at least one of the circuit and the processor configured to cause the data transmission system to:

divide data, which is provided from one of the two electronic devices, into a packet after the data transmission direction of the bidirectional transmission path is preliminarily set by the user;

determine whether or not the first unidirectional transmission path executes the data transmission after the data is divided into the packet;

transmit the packet to the other of the two electronic devices via the first unidirectional transmission path, in response to determining that the first unidirectional transmission path does not executes the data transmission;

determine whether or not the bidirectional transmission path executes the data transmission, in response to determining that the first unidirectional transmission path executes the data transmission; and

transmit the packet to the other of the two electronic devices via the bidirectional transmission path, in response to determining that the bidirectional transmission path does not execute the data transmission.

2 . The data transmission system according to claim 1 ,

wherein the at least one of the circuit and the processor is configured to cause the data transmission system to set the data transmission direction at startup of the data transmission system.

3 . The data transmission system according to claim 1 ,

wherein the at least one of the circuit and the processor is configured to cause the data transmission system to set the data transmission direction each time a predetermined cycle time has elapsed, during the data transmission system being in operation.

4 . The data transmission system according to claim 3 , wherein:

the at least one of the circuit and the processor is configured to cause the data transmission system to:

acquire a transmission request data volume from each of the two electronic devices serving as transmission sources, and then execute comparison between the two electronic devices according to the transmission request data volume acquired from each of the two electronic devices, and

set the data transmission direction to allow one of the two electronic devices, which has a larger transmission request data volume than another one of the two electronic devices, to execute the data transmission to the other one of the two electronic devices based on a result of the comparison.

5 . The data transmission system according to claim 4 , wherein:

the at least one of the circuit and the processor is provided for each of the two electronic devices; and

the at least one of the circuit and the processor is configured to cause the data transmission system to acquire the transmission request data volume from another one of the two electronic devices via either the first unidirectional transmission path or the second unidirectional transmission path.

6 . The data transmission system according to claim 4 , further comprising:

a data-volume transmission path being different from the first unidirectional transmission path, the second unidirectional transmission path, and the bidirectional transmission path, the data-volume transmission path configured to allow transmission of the transmission request data volume from each of the two electronic devices,

wherein the at least one of the circuit and the processor is configured to cause the data transmission system to acquire the transmission request data volume via the data-volume transmission path.

7 . The data transmission system according to claim 1 , wherein

the at least one of the circuit and the processor is configured to cause the data transmission system to:

determine again whether or not the first unidirectional transmission path executes the data transmission, in response to determining that the bidirectional transmission path executes the data transmission.

8 . The data transmission system according to claim 1 , wherein

the at least one of the circuit and the processor is configured to set allow the user to set the data transmission direction of the bidirectional transmission path in advance at startup of the data transmission system.

9 . The data transmission system according to claim 1 , wherein

the bidirectional transmission path is one of bidirectional transmission paths, and

the at least one of the circuit and the processor is configured to set all of respective data transmission directions of the bidirectional transmission paths to be identical.