| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the frequency of communication for monitoring a state of an entire device without increasing the number of signal lines in an extension unit interface. <P>SOLUTION: An extension interface device is constituted in such a way that common communication signal lines connecting the device main body and respective extension units in parallel are used, a part of communication data is used as a status of state changes by each extension unit, and the plurality of extension units whose states have changed can be simultaneously return the statuses, thereby the device main body can monitor state changes of all extension units by status reception. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
