Control system and programmable logic controller

A control system, comprising:

• a camera including a first synchronous counter;
• a programmable logic controller including a second synchronous counter;
• and
• a control network connecting the camera and the programmable logic controller, the control network being configured to synchronize the first synchronous counter and the second synchronous counter by measuring durations of a plurality of transmission delays between the camera and the programmable logic controller, wherein
• the camera adds, to a captured image obtained by image capturing, a count value of the first synchronous counter at the image capturing, and transmits the captured image to the programmable logic controller through the control network, and
• the programmable logic controller stores, into a storage device included in the programmable logic controller, a count value of the second synchronous counter, internal data or data of a control target, the count value of the first synchronous counter, and the captured image.