User`s manual

NPort 6000 Series User’s Manual Configuring Serial Port Operation Modes
7-9
ATTENTION
If used, the Inactivity time setting should be greater than the Force transmit time. To prevent
the unintended loss of data due to the session being disconnected, it is highly recommended that
this value is set large enough so that the intended data transfer is completed.
Max connection (default=1): This field is used if you need to receive data from different hosts
simultaneously. When set to 1, only a single host may open the TCP connection to the serial port.
When set to 2 or greater, up to the specified number of hosts may open this port at the same time.
When multiple hosts establish a TCP connection to the serial port at the same time, the NPort 6000
will duplicate the serial data and transmit it to all the hosts. Ethernet data is sent on a first-in
first-out basis to the serial port when data comes into the NPort 6000 from the Ethernet interface.
Ignore jammed IP (default=No): This option determines how the port will proceed if multiple
hosts are connected and one or more of the hosts stops responding as the port is transmitting data.
If you select No, the port will wait until the data has been transmitted successfully to all hosts
before transmitting the next group of data. If you select Yes , the port will ignore the host that
stopped responding and continue data transmission to the other hosts.
Allow driver control (default=No): This option determines how the port will proceed if driver
control commands are received from multiple hosts that are connected to the port. If No is selected,
driver control commands will be ignored. If Yes is selected, control commands will be accepted,
with the most recent command received taking precedence.
Command by command operation (default=Disable): Command by command mode can only
support one request and one response from each of the different hosts. When the NPort 6000
receives the command from any host on the Ethernet, the NPort 6000 will store all the commands
in the buffer and then send to serial ports in FIFO (First In, First Out) order.
Host B COM5
Host A COM3
PLC
: from Host A
: from Host B
Once the PLC responds, the NPort 6000 will store the response in its buffer, decide that the
response has been received, and then send back the command. The NPort 6000 will then be free to
process the next command.