Industrial network system comprising multiple communication devices, the multiple communication devices comprising multiple slave devices (100; 100A) and a master device (200; 200A); each of the multiple slave devices (100; 100A) comprising: a first communication unit for communicating with a first device, which is a master device (200; 200A) or a slave device; and a second communication unit for communicating with a second device, which is a master device (200; 200A) or a slave device; wherein the first communication unit and the second communication unit are configured, when their corresponding slave device (100; 100A) is turned on, to start an operation for transmitting a link pulse at a predetermined timing at least once so as to establish a link with the communication counterpart device, the first communication unit performs the operation during a time period from a point in time when the slave device (100; 100A) is turned on to a given point in time, and the slave device (100; 100A) further includes a reset processing unit (130; 130A) configured to perform, immediately after the time period, reset processing for letting the first communication unit newly start the operation if the time period has elapsed without the link between the first communication unit and the first device being established, wherein the first communication unit is a communication unit on the communication downstream side being the side far away from the master device (200; 200A), and the second communication unit is a communication unit on the communication upstream side being the side closest to the master device (200; 200A), the given point in time is a point in time at which a reset request transmitted by the master device (200; 200A) is received, and the reset processing unit (130; 130A) resets the first communication unit immediately after the time period in accordance with the reset request. a first communication unit for communicating with a first device, which is a master device (200; 200A) or a slave device; and a second communication unit for communicating with a second device, which is a master device (200; 200A) or a slave device; wherein the first communication unit and the second communication unit are configured, when their corresponding slave device (100; 100A) is turned on, to start an operation for transmitting a link pulse at a predetermined timing at least once so as to establish a link with the communication counterpart device, the first communication unit performs the operation during a time period from a point in time when the slave device (100; 100A) is turned on to a given point in time, and the slave device (100; 100A) further includes a reset processing unit (130; 130A) configured to perform, immediately after the time period, reset processing for letting the first communication unit newly start the operation if the time period has elapsed without the link between the first communication unit and the first device being established, wherein the first communication unit is a communication unit on the communication downstream side being the side far away from the master device (200; 200A), and the second communication unit is a communication unit on the communication upstream side being the side closest to the master device (200; 200A), the given point in time is a point in time at which a reset request transmitted by the master device (200; 200A) is received, and the reset processing unit (130; 130A) resets the first communication unit immediately after the time period in accordance with the reset request.