Allen-Bradley AADvance, Руководство пользователя

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Rockwell Automation Publication ICSTT-RM448J-EN-P - April 2018 21
The AADvance Safety Controller Chapter 2
Though the average scan time will be within 1 ms of the scan time calculated
above the calculation does not take into account the effects of application logic
and network communication, and individual scans can vary by up to +/- 4 ms
around the average scan time.
Throughput time is the time from input change to output action. For
asynchronous inputs the throughput times can be derived from the Scan time
calculated above according to the following formulae:
• Minimum throughput time = Scan 7 ms
• Maximum throughput time = 2 x Scan time + 13 ms
An example configuration scan time:
System configuration includes T9432 Analogue input simplex modules x 30
and T9451 Digital output simplex modules x 18.
Total I/O modules = 48
Sync time = 32 ms
Scan time = 39.3 ms + 32 ms + (48 x 0.04) ms + (30 x 1.170) ms + (18 x
1.174) ms => 129.5 ms
Minimum throughput time = 129.5 ms + 7 ms => 136.5 ms
Maximum throughput time = (2 x 129.5) ms + 13 ms = 272.0 ms.
System Installation
Environment The installation environment can be a source of common cause failure so it is
necessary that the installation assessment covers the environmental
specification for the AADvance system and includes the following:
• the prevailing climatic conditions
• type of area, e.g. is it a hazardous or non-hazardous area
• location of power sources
• earthing and EMC conditions
In some customer installations parts of the system can be installed in differing
locations; in these cases the assessment must include each location.
Power Sources and Heat Dissipation Calculations
It is highly recommended that module supply power and field loop power
consumption calculations are done to find out the heat dissipation before
designing a suitable enclosure and making a decision about the installation
environment (see topic "System Design for Heat Dissipation").
41..48 modules 32 ms.