Rockwell Automation 1757-SWKIT4000 ProcessLogix R400.0 Installation and Upgrade Guide - Manual (Page 268)

Publication 1757-IN040B-EN-P - March 2002
11-16 Performance and Capacity Specifications
Controller Communications
Note that with the addition of the 1757-FIM, which uses CDA for
communications, the terms “1757-PLX52 Controller” and “CPM” refer
not only to the CPM, but also to the 1757-FIM, if not explicitly noted.
For example, the Maximum Total Parameter Access Response Rate to
the Server from all Controllers combined is the total response rate
from all 1757-PLX52s and 1757-FIMs in the system combined.
•
Each 1757-PLX52 Controller can be the initiator of up to 5
peer-to-peer connections to other 1757-PLX52 Controllers.
•
Each 1757-PLX52 Controller can be the target of up to 5
peer-to-peer connections from other 1757-PLX52 Controllers.
Table 11.J 1757-PLX52 Controller Communications Performance
1757-PLX52 Controller Communications Performance
PPS = Average Parameters per Second
Overall Communications Performance per
ProcessLogix Server 50 ms CEE 5 ms CEE
Maximum Total Parameter Access Response Rate to
the Server from all 1757-PLX52s and 1757-FIMs
Controllers combined.
(Includes Display updates, Fast/Slow History, Excel I/ODBC
Exchange, and CB Monitoring)
4000 PPS 4000 PPS
Overall Communications Performance per
1757-PLX52 50 ms CEE 5 ms CEE
Maximum Total Parameter Access Response Rate
(Includes all Server Data Requests and peer communications,
including other 1757-PLX52s and 1757-FIMs)
2000 PPS 2000 PPS
1757-PLX52 to 1757-PLX52 peer to peer
Communications Performance per 1757-PLX52 50 ms 5 ms
Because Ethernet is inherently a non-deterministic network, no guarantees can be made about
the timely delivery of critical data packets. The support of TCP/IP Ethernet as the Supervisory
network in ProcessLogix does not preclude the customer to design and configure a mission
critical control strategy based upon Ethernet.
•
Ethernet is not a deterministic network, consider these factors before employing a
mission critical control strategy: Ethernet is subject to collisions, deferred
transmissions, and other anomalies, which may delay the arrival of critical data packets
•
Internal testing has shown that under a full load condition, approximately 1 in 30,000
peer fetches arrive at a peer node at greater than twice the configured peer update
rate.
Maximum Initiator Node Pull/Get Request Rate to all
target nodes.
(Based on the number of requests for peer data and the peer
update rate.)
The 1757-FIM from 1757-PLX52 is Pull and is fixed at
100ms. The 1757-PLX52 from 1757-FIM is Pull and
published on receipt by the 1757-FIM from FFD.
500 PPS 500 PPS