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Chapter 6
CGCM-DLR Unit Software Interface
152
Unscheduled Read Data Table
The Unscheduled Read data table contains metering and other non time-critical
status data that is read from the CGCM-DLR unit by the ControlLogix
controller.
The host controller reads the data in this Controller Tag from the unit by using
unscheduled messaging that is controlled by the user program.
Data Type
Create the Unscheduled Read data table by using module-defined data type
AB:1407_CGCM:Unscheduled_Read3.
Unscheduled Read Data Table
The Get Attributes Single service for instance 5 of the Assembly Object
(Class 0x04) can access the following information.
Table 11 - Get Attributes Single (Service Code 0x0E)
Name
Attribute ID
Data
3
Size
4
The Set Attributes Single service is not supported for instance 5.
Configuration Checking
No range checks are performed on this data table.
Energy Metering Considerations
Energy metering values (kW_Hrs, kVAR_Hrs, and kVA_Hrs) are provided using
a REAL data type. Values are expressed in a 32-bit floating point format with a
precision of seven digits. The table lists the theoretical range of a REAL value.
The energy values accumulate when the average generator line current is no less
than 1% of generator rated current. The limit that can be shown by an energy tag
is expressed by the following formulas:
kVA_Hrs Limit
kW_Hrs Limit
=
kVAR_Hrs Limit
When the energy tag value reaches (8,388,600 * rated kVA * % of rated load) and
the unit is still providing the same load level or less, the value does not update.
Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
Data Type
UINT
UINT
⋅
=
8,338,600 rated kVA
⋅
8,338,600 rated kW
⋅
=
8,338,600 rated kVAR
Value
See Unscheduled Read Data Table, Assembly
Instance 5
172
⋅
(
)
% of rated load
⋅
(
)
% of rated load
⋅
(
% of rated load
)
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