Communications capacity and performance, Controller communications – Rockwell Automation 1757-SWKIT3200 ProcessLogix R320.0 Installation and Upgrade Guide User Manual
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Publication 1757-IN032B-EN-P - April 2001
Performance and Capacity Specifications 7-11
Communications Capacity
and Performance
Controller Communications
Table 7.L 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 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)
2000 PPS
2000 PPS
1757-PLX52 to 1757-PLX52 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.)
500 PPS
500 PPS
Maximum Initiator Node Pull/Get Request Rate to all
target nodes. (ControlNet)
50 @ 100 ms
100 @ 200 ms
250 @ 500 ms
500 @ 1 sec
5 @ 10 ms
10 @ 20 ms
25 @ 50 ms
50 @ 100 ms
100 @ 200 ms
250 @ 500 ms
500 @ 1 sec
Maximum Initiator Node Pull/Get Request Rate to all
target nodes. (Ethernet)
250 @ 500 ms
500 @ 1 sec
250 @ 500 ms
500 @ 1 sec
Maximum Target Node Response Rate to Pull/Get
Requests from all initiator nodes.
500 PPS
500 PPS
Maximum Initiator Node Push/Store Request Rate to
all target nodes.*
50
PPS 50
PPS