Slave device
First Claim
1. A slave device for performing master-slave communication with a master device and, in response to a data request sent from the master device, sending data requested by the data request as a response, the slave device comprising:
- a data section for storing data;
a functional operating section for updating data stored in the data section;
a data update management section for managing an update of data stored in the data section; and
a command analysis section for, in response to a data request sent from the master device,determining whether a piece of data requested by the data request among data stored in the data section has been updated after previous transmission of the piece of data,sending the updated piece of data as a response to the data request if it is determined that the piece of data have been updated after the previous transmission, andsuspending a response to the data request if it is determined that the piece of data has not been updated after the previous transmission, whereinwhile the command analysis section suspends the response to the data request, the command analysis section is configured to monitor whether the data stored in the data section is updated,in response to the data stored in the data section being updated within a predetermined period of time after the data request is sent from the master device, the command analysis section is configured to read the updated data stored in the data section and send, as the response to the data request, the updated data to the master device, andin response to the data stored in the data section not being updated within the predetermined period of time after the data request is sent from the master device, the command analysis section is configured to send, as the response to the data request, the unupdated data stored in the data section to the master device.
1 Assignment
0 Petitions
Accused Products
Abstract
When a data request is sent from a master device in master-slave communication, a slave device determines whether a piece of data requested by the data request among data stored on the slave device side has been updated after previous transmission of the piece of data. If the piece of data has been updated, the slave device sends the updated piece of data as a response to the data request. If the piece of data has not been updated, the slave device suspends a response to the data request. Thus, a communication system is built which can reduce network processing load and the volume of communication data in the case where the master device periodically acquires data from the slave device.
12 Citations
5 Claims
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1. A slave device for performing master-slave communication with a master device and, in response to a data request sent from the master device, sending data requested by the data request as a response, the slave device comprising:
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a data section for storing data; a functional operating section for updating data stored in the data section; a data update management section for managing an update of data stored in the data section; and a command analysis section for, in response to a data request sent from the master device, determining whether a piece of data requested by the data request among data stored in the data section has been updated after previous transmission of the piece of data, sending the updated piece of data as a response to the data request if it is determined that the piece of data have been updated after the previous transmission, and suspending a response to the data request if it is determined that the piece of data has not been updated after the previous transmission, wherein while the command analysis section suspends the response to the data request, the command analysis section is configured to monitor whether the data stored in the data section is updated, in response to the data stored in the data section being updated within a predetermined period of time after the data request is sent from the master device, the command analysis section is configured to read the updated data stored in the data section and send, as the response to the data request, the updated data to the master device, and in response to the data stored in the data section not being updated within the predetermined period of time after the data request is sent from the master device, the command analysis section is configured to send, as the response to the data request, the unupdated data stored in the data section to the master device. - View Dependent Claims (2, 3, 4, 5)
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Specification