Rockwell Automation 1757-SWKIT5000 ProcessLogix R500.1 Installation and Upgrade Guide - Manual (Page 264)

Publication 1757-IN500A-EN-P - September 2002
11-24 Performance and Capacity Specifications
FIM Performance Limits
The FIM is a complex device interfacing the high-speed ProcessLogix internal
networks to the 31.25 Kbps FF H1 links. It uses an advanced caching scheme
to maintain quick response to reasonably fresh values and maintains
communications with the multiple FF devices as time permits in the prioritized
scheme of the Link Schedule based on FF specification requirements. This
table describes limits of performance through the FIM.
The FIM cache (one for both links) holds 800 items. An item can be:
• A simple parameter
• A structured parameter
• An arrayed parameter
Quality of service is based on priorities (highest to lowest).
• Incoming H1 Subscriptions and outgoing H1 Publications, per LAS
• H1 Alerts
• H1 Writes
• New H1 reads (and re-written parameters)
• H1 Re-reads to refresh the cache
Table 11.U 1757-FIM Performance Limits
FIM Performance Limits Per FIM Per Link Per Device
Burst Sustained Burst Sustained Burst Sustained
H1 Link Publication Rate (parameters/second, pps) ---
32
(1) ---
16
(1) ---
16
(1)
Client-Server Store Rate
(1)
(pps) [excludes publications from
ProcessLogix function blocks]
40
10
(5) 20
5
(5) 4
1
(5)
Max number of slow history points.
(1) --- 40 ---
20
(6) ---
20
(6)
Max number of read-activities per second.
(1)
• A read-activity includes any or all of a block view list parameters or
a single non-viewed parameter.
• Includes all users such as slow history, SCM connections to
non-published parameters, Excel or OPC reads of non-published
parameters, etc.
10 10 5 5 2 2
Maximum number of parameters read per second.
(1)(2)
• Includes all users such as CM connections to non-output
parameters (e.g. tuning constants or limits),
• SCM connections to non-published parameters, Excel or OPC reads
of non-published parameters, etc.
80 80 40 40 16 16
Maximum Alert Rate per second. (Alarm and Return-to-Normal
reports)
(1)(3)
‡
50 2 50 2 2 1
Maximum Number of Devices
32
(4)
†
16† ---
(1) Assumes
≥ 50% of link schedule is usable for client-server messaging.
(2) Assumes all parameters read are in view lists and the average number of parameters read and used per view is 8.
(3) Bursts are up to one minute apart.
(4) These numbers may be further limited by other restrictions noted in this document.
(5) This assumes that the FF device supports AlterEventConditionMonitoring, the ability to suppress Update Events. Otherwise reduce by factor of 2.
(6) All parameters must be in one view list per device or published