Allen-Bradley 1756-CFM, Руководство пользователя

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Rockwell Automation Publication 1756-UM010C-EN-P - June 2021 25
Chapter 3 Configurable Flowmeter Module Features and Operational Modes
Compatible Keying
Compatible Keying indicates that the module determines whether to accept or
reject communication. Different module families, communication adapters,
and module types implement the compatibility check differently based on the
family capabilities and on prior knowledge of compatible products. Release
notes for individual modules indicate the specific compatibility details.
Compatible Keying is the default setting. Compatible Keying allows the
physical module to accept the key of the module configured in the software,
provided that the configured module is one the physical module is capable of
emulating. The exact level of emulation required is product and revision
specific.
With Compatible Keying, you can replace a module of a certain Major Revision
with one of the same catalog number and the same or later, that is higher,
Major Revision. In some cases, the selection makes it possible to use a
replacement that is a different catalog number than the original. For example,
you can replace a 1756-CNBR module with a 1756-CN2R module.
When a module is created, the module developers consider the module’s
development history to implement capabilities that emulate those of the
previous module. However, the developers cannot know future developments.
Because of this, when a system is configured, we recommend that you
configure your module using the earliest, that is, lowest, revision of the
physical module that you believe will be used in the system. By doing this, you
can avoid the case of a physical module rejecting the keying request because it
is an earlier revision than the one configured in the software.
EXAMPLE In this scenario, Compatible Keying prevents I/O communication :
The module configuration is for a 1756-IB16D module with module revision
3.3. The physical module is a 1756-IB16D module with module revision 3.2.
In this case, communication is prevented because the minor revision of
the module is lower than expected and may not be compatible with 3.3.
Module Configuration
Vendor = Allen-Bradley
Product Type = Digital Input Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 3
Physical Module
Vendor = Allen-Bradley
Product Type = Digital Input Module
Catalog Number = 1756-IB16D
Major Revision = 3
Minor Revision = 2
Communication is prevented.