Rockwell Automation 1425 PowerMonitor Wireless 250 User Manual
Page 37
Rockwell Automation Publication 1425-UM001A-EN-P - January 2012
37
Software Interface
Chapter 3
Comments on PowerMonitor W250 Modbus Register Tables
The following sections provide comments on the Modbus register tables.
Energy Usage Data (Register 0…23)
These registers contain the raw, unscaled total consumed energy measured by the
PowerMonitor W250 unit. The scaling factors listed in the next section must be
applied to obtain energy values in the applicable engineering units of wH, VARh,
and VAh. The energy counter time-stamp indicates when the data is sent to the
gateway.
Energy usage data increments positive for energy consumed and negative for
energy generated.
Real, reactive, and apparent energy consumption values are stored as 32-bit
integer values using two Modbus registers. The lower register address contains
the high (most significant) word (MSW), the higher register contains the low
(least significant) word value (LSW).
for information on scaling the raw energy values in these
registers.
Table 15 - Information for
Term
Description
Comments
NV
Non-volatile
Value is restored after a power cycle
V
Volatile
Value is not restored after a power cycle
S16
Signed 16-bit INT
Range -32,768…32767
U16
Unsigned 16-bit INT
Range 0…65,535
S32
Signed 32-bit INT
Range -2,147,483,648…2,147,483,647
U32
Unsigned 32-bit INT
Range 0…4,294,967,297
MSW
Most Significant Word
LSW
Least Significant Word
Table 16 - Energy Counters
0, 2, …22
1, 3, …23
MSW LSW