Tab: Modbus Serial Client – General

The tab includes the basic settings for Modbus communication.

Table 2. Modbus RTU/ASCII

Transmission mode	RTU: Transmission in binary form ASCII: Transmission in ASCII code (currently not supported by all drivers)
Response timeout (ms)	Time interval for the client to wait for the response from a server node. If the nodes do not respond within this time span, then an error is issued for the implicit server FB. The value specified for the time span is also the default value for each node. For each node, you can still set a specific value within its server configuration.
Time between frames (ms)	The time between the frames is the send pause of the client between the last response (and a timeout) and the next request. Use this parameter to make the communication less liable to disruption.
Auto-restart communication	: After a communication error, CODESYS automatically confirms the error and attempts to continue executing the Modbus command. : The error has to be acknowledged explicitly in the server function block.