1. Technical Field
The present invention relates to a system including a plurality of storage devices, and more particularly, to a data transmission technique for the system.
2. Related Art
An ink container which is a detachable liquid container is generally mounted on an ink jet printing apparatus which is an example of a liquid ejecting apparatus. A storage device is installed in some ink containers. The storage device stores various kinds of information such as the amount of ink remaining in the ink container or the ink colors (JP-A-2002-370383 and JP-A-2004-299405). A control device installed in the printing apparatus communicates with the storage device of the ink container.
In the known technique, however, the reliability of communication between the control device installed in the printing apparatus and the storage device of the ink container is hardly taken into consideration. For example, a problem may arise in that the communication between the control device installed in the printing apparatus and the storage device of the ink container may fail due to the contact failure of an electric connection portion between the printing apparatus and the ink container. When the printing apparatus continues an operation in the communication failure state, a problem may arise where a fault occurs in the stored details of the storage device.
In general, it is desirable that the data transmission speed is as rapid as possible. For example, the data transmission speed can be made more rapid by increasing the clock frequency of data transmission. However, when the clock frequency is excessively increased, a problem may arise in that consumed current flowing in a data line is excessively increased. In an example according to the related art, little consideration was paid to the consumed current necessary for communication (data transmission) between the control device and the storage device. When the consumed current necessary for communication between the control device and the storage device is reduced, current capacity of a data transmission circuit can be reduced. Therefore, since the configuration of the circuit can be simplified, an advantage can be obtained so problems with heating or noise hardly occur. In an example according to the related art, however, the study regarding this point is not sufficiently conducted.
The above-mentioned problems occur not only in the printing apparatus but also in the system including a plurality of storage devices.