Communication system with master and slave exchanging control data in predetermined communication period

A master/slave communication system comprising:

• at least one slave;
• and
• a master to which the at least one slave is connected to the master through a serial transmission line, control data being exchanged between the at least one slave and the master in a predetermined communication period,
• wherein in the predetermined communication period and after the master executes exchange of the control data with respect to the at least one slave, the master re-executes exchange of the control data with respect to a resending slave which is stored when an error is detected in the resending slave during exchange of the control data and to which resending of the control data needs to be performed.

A master/slave communication method for a master/slave communication system, the master/slave communication system comprising:

• at least one slave;
• and
• a master to which the at least one slave is connected through a serial transmission line, control data being exchanged between the at least one slave and the master in a predetermined communication period, the master comprising:
• a slave information storage to store slave information of the at least one slave, the slave information including an expected communication time needed to exchange the control data;
• and;
• a resending slave information storage to store resending slave information including a remaining resending time and a resending slave in which an error is detected during exchange of the control data and to which resending needs to be performed,
• said master/slave communication method comprising:
• executing, by the master, in the predetermined communication period, exchange of the control data with respect to the at least one slave based on the slave information, and then
• re-executing exchange of the control data with respect to the resending slave based on the resending slave information.

A master/slave communication method for a master/slave communication system, the master/slave communication system comprising:

• at least one slave;
• and
• a master to which the at least one slave is connected through a serial transmission line, control data being exchanged between the at least one slave and the master in a predetermined communication period,
• said master/slave communication method comprising:
• re-executing, by the master, in the predetermined communication period and after the master executes exchange of the control data with respect to the at least one slave, exchange of the control data with respect to a resending slave which is stored when an error is detected in the resending slave during exchange of the control data and to which resending of the control data needs to be performed.

A master/slave communication method for a master/slave communication system, the master/slave communication system comprising:

• at least one slave;
• and
• a master to which the at least one slave is connected through a serial transmission line, control data being exchanged between the at least one slave and the master in a predetermined communication period,
• the method comprising:
• sending the control data to the at least one slave as processing executed by the master in the predetermined communication period;
• receiving, by the master, the control data from the at least one slave;
• repeating, for the at least one slave, unconditionally registering the at least one slave as a target to which resending is to be performed when an error is detected in the sending step or in the receiving step;
• extracting information regarding the at least one slave registered as the target to which resending is to be performed;
• comparing a remaining resending time that can be used to re-execute exchange of the control data with an expected communication time needed to exchange the control data of the slave;
• and
• re-executing exchange of the control data when the remaining resending time is longer than the expected communication time of the registered slave.

A master/slave communication method for a master/slave communication system, the master/slave communication system comprising:

• at least one slave;
• and
• a master to which the at least one slave is connected through a serial transmission line, control data being exchanged between the at least one slave and the master in a predetermined communication period,
• the method comprising:
• sending the control data to the at least one slave as processing executed by the master in the predetermined communication period;
• receiving, by the master, the control data from the at least one slave;
• repeating, when a communication error is detected in the at least one slave in the sending step or in the receiving step, registering the error-detected at least one slave as a target to which resending is to be performed when a remaining resending time that can be used to re-execute exchange of the control data is longer than an expected communication time needed to exchange the control data of the at least one slave;
• extracting information regarding the at least one slave registered as the target to which resending is to be performed;
• re-executing exchange of the control data with the at least one slave registered as the target to which resending is to be performed.