Please refer to the following explanation: 1.Communication Delay Time: This function sets the delay time to wait for the startup of an external controller (i.e. PLC). The range of the communication delay time is between 0 ~ 255ms and the default setting is 0ms. When the communication delay time is set to 0ms, the waveform of the communication signal looks like the figure below. After the device feeds back the signal, the HMI sends the next communication request 4ms later. When the communication delay time is set to 10ms, the waveform of the communication signal looks like the figure below. After the PLC feeds back the command, the HMI sends the next communication request 14ms later. It indicates that every communication request sent by the HMI will delay 10ms. When the connecting PLC cannot respond to each communication request from the HMI in real time, users can use this function to let the device have more time to prepare and respond to the communication. 2.Timeout (ms): This function sets the communication timeout time when communicating with the PLC. When there is no response from the PLC after a certain period of time, it means that the communication has failed and the period of time the PLC has no response is defined as a Timeout. The range of timeout is 10ms ~ 2000ms and the default setting is 300ms. When the timeout is set to 1000ms and the HMI has sent the communication request after 1000ms, if there is no response from PLC, the HMI will resend the next communication request. The communication signal's waveform looks like the figure below. 3.Retry Count : If there is no response from the PLC after the communication starts, the HMI resends the communication command. If the preset retry count has been reached, the HMI displays a warning message to alert the system. The range of retry count is 0 ~ 15 times and the default setting is 3 times. When the preset retry count is set to 2 and if the communication fails after 2 retries, the communication signal's waveform looks like the figure below.