Allen-Bradley 1407-CGCM, User Manual, Page: 141 / 252

Rockwell Automation Publication 1407-UM001H-EN-P - November 2014
CGCM Unit Software Interface #HAPTER
5NSCHEDULED2EAD$ATA4ABLE
The Get Attributes Single service for instance 5 of the Assembly Object can
access the following information.
The Set Attributes Single service is not supported for instance 5.
#ONFIGURATION#HECKING
No range checking is performed on this data table.
%NERGY-ETERING#ONSIDERATIONS
Energy metering values (kW_Hrs, kVAR_Hrs, and kVA_Hrs) are provided using
a REAL data type. Values are expressed in a 32-bit floating-point format with a
precision of 7 digits. The table lists the theoretical range of a REAL value.
The energy values accumulate when the average generator line current is no less
than 1% of generator rated current. The limit that can be represented by an
energy tag is expressed by the following formulas:
When the energy tag value reaches (8,388,600 * rated kVA * % of rated load) and
the unit is still providing the same load level or less, the value will not update.
For instance, a 30 MVA machine operating at 10% load will yield an energy tag
limit of :
(8,338,600 * .1 * 30000) = 25,015,800,000 kVAh, or 2.50158 x 10
10
kVAh
When the energy tag value exceeds 8,338,600, rounding of the value begins to
occur.
The energy values are not retentive. When the 1407-CGCM unit powers up or
re-establishes a connection with the controller, the energy presets in the
Unscheduled Write table are written to the energy metering values.
4ABLE'ET!TTRIBUTES3INGLESERVICECODEX%
.AME !TTRIBUTE)$ $ATA4YPE 6ALUE
Data 3 UINT See Unscheduled Read Data Table,
Assembly Instance 5
Size 4 UINT 172
kW_Hrs Limit 8,338,600 rated kW % of rated load
– –
=
kVAR_Hrs Limit 8,338,600 rated kVAR % of rated load
– –
=
kVA_Hrs Limit 8,338,600 rated kVA % of rated load
– –
=