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ST5/10-Si,-Q,-C, IP Hardware manual
920-0004 Rev. C
4/21/11
time. Ports are used to direct traffic to the right application once it gets to the right IP address. The UDP
eSCL port in our drives is 7775. To send and receive commands using TCP, use port number 7776. You’ll
need to know this when you begin to write your own application. You will also need to choose an open
(unused) port number for your application. Our drive doesn’t care what that is; when the first command is
sent to the drive, the drive will make note of the IP address and port number from which it originated and
direct any responses there. The drive will also refuse any traffic from other IP addresses that is headed for
the eSCL port. The first application to talk to a drive “owns” the drive. This lock is only reset when the drive
powers down.
If you need help choosing a port number for your application, you can find a list of commonly used port
numbers at http://www.iana.org/assignments/port-numbers.
One final note: Ethernet communication can use one or both of two “transport protocols”: UDP and TCP.
eSCL commands can be sent and received using either protocol. UDP is simpler and more efficient than
TCP, but TCP is more reliable on large or very busy networks where UDP packets might occasionally be
dropped.
Option 1: Connect a Drive to Your Local Area Network
If you have a spare port on a switch or router and if you are able to set your drive to an IP address that is
compatible with your network, and not used by anything else, this is a simple way to get connected. This
technique also allows you to connect multiple drives to your PC. If you are on a corporate network, please
check with your system administrator before connecting anything new to the network. He or she should be
able assign you a suitable address and help you get going.
If you are not sure which addresses are already used on your network, you can find out using “Angry IP
scanner”, which can be downloaded free from http://www.angryip.org/w/Download. But be careful: an
address might appear to be unused because a computer or other device is currently turned off. And many
networks use dynamic addressing where a DHCP server assigns addresses “on demand”. The address you
choose for your drive might get assigned to something else by the DHCP server at another time.
PC
NIC
SWITCH
or
ROUTER
LAN
DRIVE