As of CBP 2.4:

For Modbus TCP/IP protocol configuration double-click the Modbus item in the device tree and select the tab Modbus TCP/IP Server Configuration:

The following parameters are available:

Parameter	Default	Value	Meaning
Server connections	0	0…X (X depending on PLC)	Maximum number of logical parallel connections, that are kept for connection requests by clients in operation mode as server. The value 0 means pure client mode (Modbus master) (0..X, depending on the performance of the PLC)
Task timeout	2000	100 … 6000000	Only valid for client mode. A request is canceled when no response by the server is received within this time in [ms]. (100..6000000 ms)
OMB time	1000	100 … 6000000	Only valid for server mode. Determining how long a logical connection in [ms] remains after receiving the reply message of a client. Establishing and terminating of connection takes some time. When the data communication between the controller and the servers should take place only at long intervals, it is useful to close the connection immediately after completion of the data communication. (100..6000000 ms)
Send timeout	0	0 … 2000000000	Only valid for client mode. Determining how long the controller should try to send a request to a server. (0..2000000000 ms)
Connect timeout	0	0 … 2000000000	Only valid for client mode. Determining how long the controller should try to create a TCP connection with a server. (0..2000000000 ms)
Close timeout	0	0 … 2000000000	Only valid for client mode. Determining how long the controller should try to close a TCP connection with a server. (0..2000000000 ms)
Byte order	Big endian	Little endian	Valid for client and server mode. Format of the transfer of word values (registers) in the telegram. Depending on the settings, the byte order will be changed by sending and receiving. Changing the byte order may be required e.g. when devices with different processor types are used.
		Big endian