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Rockwell Automation Publication 2080-UM002N-EN-E - November 2022
Appendix G Connect to Networks using DF1
Configure the Store and Forward Table
The Store and Forward function in Micro800 controllers provide two methods to configure –
Dynamic, which requires creating a Store & Forward table, or Static, which you can directly
configure in Connected Components Workbench software.
Use the static method when you want to configure the Store and Forward tables while the
controller is offline. Use the dynamic method when you want to configure the Store and
Forward tables while the controller is in RUN mode. The dynamic Store and Forward table
occupies a BOOL array [0…255] or DWORD array [0…7] data type. Each bit in this array
corresponds to a DF1 Radio Modem node address.
In order to configure a Micro800 controller to Store and Forward message packets between
two other nodes, the bits corresponding to the addresses of those two other nodes must be
set. For instance, if node 2 is used to Store and Forward message packets between nodes 1
and 3, then both Bit 1 and Bit 3 would have to be set in the Store and Forward table (see
).
Figure 33 - Applying Store and Forward with DF1 Radio Modem Protocol
IMPORTANT
Once Store and Forward is enabled, duplicate packet detection is also
automatically enabled. Whenever Store and Forward is used within a
radio modem network, every node should have Store and Forward
enabled, even if all of the bits in the file are cleared, so that duplicate
packets will be ignored.
Node 4
No Bits
Node 3
1, 2, 4
Node 2
1, 3, 4
Node 1
No Bits
CMD 1
(DST = 4, SRC = 1)
REPLY 1
(DST = 1, SRC = 4)
CMD1
(1st Rebroadcast)
Note 1
(2nd Rebroadcast)
REPLY 1
CMD 1
(2nd Rebroadcast)
(1st Rebroadcast)
REPLY 1
Note 4
Note 2
Note 1
– The link layer of Node 1 blocks the re-transmission of a packet that is received with the SRC byte equal to the receiving node’s station
address. Packets received that originate from the receiving node should never be re-transmitted.
Note 2
– To prevent Node 2 from re-transmitting a duplicate packet, the link layer of Node 2 updates the duplicate packet table with the last 20
packets received.
Note 3
– The link layer of Node 4 blocks the re-transmission of a packet that is received with the SRC byte equal to the receiving node’s station
address. Packets received that originate from the receiving node should never be re-transmitted.
Note 4
– To prevent Node 3 from re-transmitting a duplicate packet, the link layer of Node 3 updates the duplicate packet table with the last 20
packets received.
Note 3