Rockwell Automation T3831 ICS Regent Communications Package for Winterpret - Manual (Page 6)

Communications Package for W INTERPRET (T3831)
6
Industrial Control Services
Input Data Buffers
Each Regent connected to a GPL network with “L” legs has
2*L input data buffers for each node on the network
(including itself). For example a GPL network with two legs
(dual redundant) has 4 input data buffers for each node (two
for each leg). Each of these data buffers is the size of the GPL
data packet from the associated node. Figure 4 illustrates the
structure of the GPL input data buffers in each Regent
configured for Guarded Peer-Link communications.
Figure 4. Structure of the GPL Input Data Buffers.
When an incoming GPL data packet is received it is stored in
one of the two buffers for the leg of the network the data was
received and the input data buffer is marked as “most recent.”
The previous “most recent” input data buffer is marked as
“empty.” At the end of the application program scan, the
Regent will use the input data buffer that is marked as most