Placing the Adapter into Service
 
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Initialization and Self-Tests
When the adapter receives its initial operating power from its I/O base, it performs internal initialization and self-tests. If the tests fail, the RUN indicator flashes to indicate the failure reason, if possible, and the adapter remains offline. If the tests are successful, the adapter attempts to obtain its Ethernet IP address.
Assigning an Ethernet IP Address
Overview: Address Assignment
A BOOTP server is required to assign a new IP address to the adapter. After the server assigns the IP address, the server application can issue a command to the adapter to cause it to store the address internally.
If the adapter has stored its address and is re-initialized (for example, following a power loss), the adapter will re-issue requests for an address from a BOOTP server. If a server responds with an address, the adapter will use that address. If a server does not respond, the adapter will revert to its stored address.
Requesting the IP Address
After completing its initialization, the adapter requests its Ethernet IP address from a BOOTP server. The adapter uses its MAC address with the BOOTP protocol over the Ethernet network.
Receiving the Server Response
The adapter will wait 10 seconds for a BOOTP server to respond with the adapter’s IP address. If the server response is received, the adapter will use that address as long as power remains applied to the adapter.
CAUTION
UNINTENDED OPERATION — DUPLICATE IP ADDRESS
  • Ensure that this device will receive a unique IP address.
  • Before removing a 170ENT11002 (170ENT11000) adapter from service, you should first write a logical 0 (zero) into the parameter storage register 4F411 to clear the adapter's stored parameters. This will reduce the possibility of a duplicate address appearing on your network if the adapter is later restored to service.
  • Refer to Communication Access Registers for a description of the 170ENT11002 (170ENT11000) adapter's registers, including how to clear the adapter's stored parameters.
Having two or more devices with the same IP address can cause unpredictable operation of your network.
Failure to follow these instructions can result in injury or equipment damage.
Retries to the Server
If a BOOTP server response is not received, the adapter will retry the request six times: three times using the Ethernet II framing type, and three times using the 802.3SNAP framing type.
Server Response Not Received (IP Address Previously Stored
If the adapter receives no response to any of its attempts to obtain an IP address and if an address has been previously stored by a Modbus Write command from the application, the adapter will then use that stored address.
Server Response Not Received (IP Address Not Stored
If the adapter receives no response to any of its attempts to obtain an IP address, and if it does not have any stored address, the adapter will continue to retry the BOOTP request every 30 seconds. During this time it will flash its RUN indicator in the requesting pattern (a sequence of five flashes).
Identifying the I/O Base
After the adapter receives its IP address, it runs an internal procedure to identify its I/O base. If the procedure fails, the adapter’s RUN indicator flashes a failure pattern (six flashes) and will remain offline.
If the I/O base is successfully identified, the adapter is ready to communicate using the Modbus protocol over TCP/IP.
Storing the IP Address in the Adapter
The adapter has a non-volatile RAM area for storing its assigned IP address. If the application requires the adapter to retain its current IP address, the application must issue a Modbus write command to write a boolean value into a specific register in the adapter to cause the address to be stored. The adapter’s default state is to not store the address.
Communication Access Registers describes how to store the IP address and how to determine if an address has been previously stored.