MSD-402 Command Guide
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2.2.4 The number of TCP-IP connections
The MSD series can connect up to eight connections (eight ports) simultaneously. If the MSD is controlled
from nine or more PCs, they may not be connected to the MSD normally, since the number of connections
that can be used is limited.
If you use nine connections or more, execute TCP-IP connection/close every time the communication
command is sent or received from the software of user
’s side. By doing so, MSD’s ports are occupied or
released so that nine or more connections can be connected logically.
[Table 2.3] Increasing connections
Your PC software
MSD
TCP-IP connection
→
(Occupied by 1 port)
Send command (@xxx)
→
←
Send back command
(@xxx)
TCP-IP close
→
(Release 1 port)
Note:
If any command is not sent from the PC side to the MSD for 30 seconds, the MSD disconnects the
connection to avoid the limitation problem on the number of connections. As a result, connection needs
to be established again from the PC side after the current connection of the PC is disconnected.
(Since the number of ports in the MSD is eight, ports are occupied permanently if the PC is turned off
while connections are valid. To prevent this, the MSD disconnects connections if no communication
command is sent from the PC side.)
