CTI 2500 Installation and Operation Guide V2.8
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7.4.4 Duplicate IP Address Detection
The controller will attempt to determine if there is another device on the network with the same
IP address as the one stored in flash in the following situations:
•
The controller is powered up with a non-zero IP address,
•
The IP address is changed to value other than zero,
•
The Ethernet Link transitions from Unconnected to Connected.
If a duplicate address is detected, the Network Status (NS) LED color will change to red and the
associated bit in STW244 will be set.
NOTE:
This is a warning only; the local port will continue to use the static IP address.
Because a duplicate IP address can disrupt communications with the local Ethernet port, you
should determine the cause of the problem and correct it by one of the following:
•
Detaching the offending device from the network,
•
changing the IP address of the offending device, or
•
Changing the IP address of the controller Ethernet port to one that is not a duplicate.
The controller may not detect a duplicate IP address in every case. For example, devices can
be added to the network while the Ethernet link is connected and operating normally. Also,
some older devices may not respond to a duplicate IP address probe message.
7.4.5 TCP Port Number Support
TCP/IP provides for multiple logical ports. Each “port” represents a particular service offered at
the IP address. The CTI 2500 Controller supports the following logical ports:
Programming Port (TCP Port 4452)
The programming port is intended for use with network-capable programming software, such as
PLC WorkShop. To use the programming port, connect to TCP port 4452. This port supports all
programming, data access, and control requests. Only one client may be connected to the
programming port at a time. The CTI 2500 gives priority to all requests to the port 4452. UDP is
not supported.
When programming via local Ethernet port using TCP port 4452, you can prevent anyone else
from concurrently modifying the program via another communications port or SF module by
enabling
P
ORT
L
OCKOUT
using your programming software. When
P
ORT
L
OCKOUT
is enabled,
requests to modify the user program originating from other physical ports or special function
modules are rejected.
SW6 must be in the open position to prevent other users of the local Ethernet port from
modifying the user program. See Section 2.3 for additional information.
