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ESP-4 MI Serial Hub Installer/User Guide
Table 3.3 describes this method’s configurable items for each serial port.
Raw TCP client
The raw TCP client connection method allows the ESP-4 MI hub to make a TCP-based connection
to a remote server and then transmit/receive data using standard TCP. The client hub initiates the
TCP session.
When this method is enabled, the raw TCP client will attempt to establish a connection with the
configured server when the connection mode requirement has been satisfied. The TCP session will
remain active until the client closes the TCP socket, the TCP connection is broken, the inactivity
Table 3.3: Raw TCP Server Connection Method Configurable Items
Item
Description
Enable/
disable
Enables or disables the raw TCP server connection method on the port. This method cannot
be enabled if the raw TCP client connection method is already enabled for the port.
The default value is disabled.
Local IP port
number
Specifies the IP port number on which the TCP server will listen. This value cannot conflict
with port numbers specified for other enabled connection methods on other ports. Valid
values are 1024-65535.
The default value is 4001 for port 1, 4002 for port 2, 4003 for port 3 and 4004 for port 4.
Inactivity time-
out
Specifies the length of time before the TCP session is disconnected if there is no activity.
Valid values are 0-65535 seconds. A 0 value disables the inactivity time-out.
For example, a value of 60 indicates the TCP session will be disconnected if there is no
activity for a period of 60 seconds.
The default value is 0 (disabled).
Monitor DCD
(Valid only on RS-232 ports.) Enables or disables monitoring of the DCD signal, which is an
indication that a serial device is attached and powered on. When enabled, the TCP server will
refuse the TCP connection if the inbound DCD signal is logically low at the time the
connection is initiated. If the inbound DCD signal changes from logically high to low while a
TCP session is active, the TCP connection will be closed.
The default value is disabled.
Serial
buffering
Specifies the length of time accumulated serial data should be buffered before being sent to
the remote server. Valid values are 0-65535 hundredths of a second. A 0 value indicates that
data will be sent as soon as it is available.
For example, a value of 100 indicates that once serial data is received, it will remain buffered
up to 1 second (100 hundredths of a second), at which time all data will be sent.
If the buffer becomes half full, the time is ignored and the data is sent.
The default value is 0 (send immediately).
Idle TCP
buffering
Enables or disables buffering of received serial data while waiting for a TCP connection to be
established. When enabled, the most recent 20K bytes of data are held in an internal buffer.
After the connection is established, the buffered serial data is sent to the TCP client. When
this option and this connection method are enabled, you may not enable any other connection
method for the port.
The default value is disabled.