In PLC applications, sometimes it is necessary to communicate with the servo. The easiest way is to use the modbus protocol through RS-232/485. This is a very cost-effective way for small systems with few axes. However, it is often a pity that the application is limited due to the lack of rapid response. For this kind of application, this article takes Delta A2 servo as an example, and provides some acceleration methods to increase the refresh rate of communication and make the command response more quickly. Interested readers can refer to it.