Detailed explanation on the communication distance of IO Link fieldbus IO

In the application of IO-Link bus I/O series products, if the project is large and the equipment is scattered, the on-site staff may encounter the situation where the IO-Link master is far away from the PLC, or the slave is far away from the master. At this time, they will have doubts about the communication distance, which will affect the site planning. In this regard, this article explains the above issues in detail.

1. Bus communication distance between IO-Link master and controller

Under the commonly used EtherCAT and PROFINET bus protocols, when using Category 5 twisted pair cables, the maximum communication distance is 100m. This communication distance depends on the bus protocol limit. If it exceeds 100m, it needs to be transferred through a switch or other transmission media, such as optical fiber.

2. Communication distance between IO-Link master and IO-Link device

IO-Link protocol follows IEC 61131-9 standard, which stipulates that the communication distance between IO-Link master and slave device is <= 20m

↑Description of master-slave distance in IEC 61131-9 standard

The main reasons are as follows:

1. IO-Link signal line is 24V level signal, and there is voltage drop in long-distance transmission;

2. IO-Link power supply is Us power supply transmitted through IO-Link harness, and the load capacity is further limited after voltage drop in long-distance transmission.