Instrumentation system and method for maintaining the same

An instrumentation system, comprising:

• a plurality of field devices, each of the field devices being configured to perform at least one of measuring and operation of a target;
• a connection device comprising a plurality of slots;
• a plurality of I/O modules being respectively attachable to the slots, the field devices being connectable to the I/O modules, each I/O module comprising a control right switcher that is coupled to the control right switcher of other of the plurality of I/O modules and being operable in a control loop;
• at least one controller coupled to the control right switcher of each I/O module and being connected to control the plurality of I/O modules;
• and
• a host control device, said host control device being configured:
• to transmit setting data to the controller to individually set the I/O modules attached to the slots to have a redundant configuration or a single configuration based on the setting data, and
• to make two I/O modules set to have the redundant configuration, among the I/O modules attached to the slots, and be paired,
• wherein the controller is configured:
• to operate the two I/O modules set to have the redundant configuration in a redundant configuration under a condition where one of the two I/O modules is in an activated state and the other of the two I/O modules is in a standby state,
• to control the transmission of normality information that indicates the states of the two I/O modules from the controller to the host control device;
• and
• to convert setting data for a first I/O module set to have the single configuration, among the I/O modules attached to the slots, to setting data that indicates that the first I/O module is set to a pseudo redundant configuration, and to operate the first I/O module in the pseudo redundant configuration under a condition where the first I/O module is operated in an activated state side of the redundant configuration, in a state where an I/O module to be paired with the first I/O module is not decided,
• wherein, when the first I/O module is operative in the pseudo redundant configuration, the first module is not paired with another I/O module,
• wherein, when the first I/O module is operative in the pseudo redundant configuration, the first I/O module is operated in an activated state, no other I/O module is set to be paired with the first I/O module, and at least one of the plurality of slots is empty;
• wherein, when the first I/O module is operative in the pseudo redundant configuration, the control right switcher of the first I/O module is operative to hold a control right and when the first I/O module is in a failure mode, the first I/O module is operative to transfer the control right to a new second I/O module inserted into said at least one empty slot when a failure occurs in the first I/O module;
• and
• wherein the first I/O module is operative to output a redundant state data to the second I/O module and thereby establish a redundant state between the first I/O module and the second I/O module,
• whereby, the first I/O unit is replaced by the second I/O unit without stopping operation of the control loop.