Omron CQM1-ARM21, Operation Manual

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Master Functionality
Section 1-2
7
1-2 Master Functionality
The master has a layered structure which is composed of three functional
parts as shown in the following figure:
Host
Host Interface
Execution Control
Transmission Control
AS-Interface line
The AS-Interface specification defines the transmission control functions, and
lists all mandatory and optional functions of the execution control. The host
interface is in principle not governed by the AS-Interface specification.
Master Profiles Furthermore, three standard levels of compliance with the standard are
defined in so-called master profiles. These are named M0, M1 and M2.
M0 The lowest level, the M0 or minimum master profile, defines the smallest set
of mandatory functions. Any AS-Interface master should at least be able to
execute these functions.
M1 The M1 or full master profile, provides all functions to fully configure an AS-
Interface network, plus transfer of most internal status information to the host
system.
M2 The M2 or reduced master profile consists of the M0 profile plus 2 additional
functions to set and store slave parameters.
The CQM1-ARM21 provides M0 functionality in standard operation mode, but
additional configuration functions are available in a special setup mode, in
which the updating of slaves’ I/O data in the PLC is partially suspended. In
setup mode, the CQM1-ARM21 acts as a configuration tool.
All masters should, as a minimum, provide the following functionality:
- Cyclically read input data from slaves, and present this data to the host.
- Cyclically read output data from the host, and transmit this data to the
slaves.
- Inform the host if the actual configuration matches the expected
(projected) configuration.
- Offer two operation modes: protected mode and configuration mode.
- Store the actual configuration data (CDI) - detected in configuration mode -
in non-volatile memory as the permanent configuration (PCD).
In protected mode, only slaves that are member of the list of projected slaves
(LPS) and whose configuration data image (CDI) and permanent
configuration data (PCD) are identical, will be activated.
In configuration mode, all detected slaves will be activated, irrespective of the
differences in the values of the configuration data image (CDI) and permanent