Automatic circulation collection type data collecting system

An automatic circulation collection type data collecting system constructed by connecting a monitor device and a data collecting module disposed at each place through an optical cable, wherein;

• the monitor device comprises a trigger pulse generator for transmitting a data-collecting trigger pulse through an optical cable to each data collecting module at a predetermined timing, a collected data withdrawing unit for receiving collected data from each data collecting module through an optical cable, and a controller for transmitting a control signal for data collection to each data collecting module;
• each data collecting module is provided with an identification code, each data collecting module has an automatic circulation mechanism comprising a first optical switch and a second optical switch, a data collecting unit for collecting data at each place, a controller connected to the data collecting unit and the optical cable, and a third optical switch for controlling on/off of the connection between the controller and the optical cable;
• each of the first optical switch and the second optical switch comprises such an optical control type optical switch as to receive light source light and signal light having a wavelength different from that of the light source light and controlling on/off of the output of the light source by on/off of the input of the signal light;
• and
• when receiving a trigger pulse from the monitor device, the automatic circulation mechanism turns on the third switch and makes the controller transmit data collected by a data collecting unit to the monitor device through the optical cable together with the identification code, and also transmits a trigger pulse through the optical cable to a next data collecting module.