Allen-Bradley Powermonitor 3000 User Manual page 155

Allen-Bradley HMIs
N
datapoint_oscillogram
N = the sequence number of the data point in the oscillogram channel
datapoint_oscillogram
N = the block number
block
N = the data point number (1 to 20 or 1 to 50) in the current read
datapoint_this_read
The total number of data points is 4600 for capture type 0, 1 and 2
and 9200 for capture types 3, 4 and 5.
Each data point is expressed in calibrated analog-to-digital (A/D)
converter counts with a resolution of 8192 (13-bit w/sign) or 128 (7-bit
w/sign). A client may calculate the primary-side instantaneous voltage
or current magnitude of each data point using the following formula:
M =
i
Where:
• M
= instantaneous value of the voltage or current data point
i
• M
= max rms magnitude
(max rms)
= 399.0 line-to-neutral volts for channels 1, 3 and 5
= 691.1 line-to-line volts for channels 1, 3 and 5
= 10.6 amperes for channels 2, 4, 6 and 7
• R
= maximum resolution
max
= 8192 for 13-bit w/sign, capture types 0, 1 and 2
= 128 for 7-bit w/sign, capture types 3, 4 and 5
• N
= PT or CT ratio
t
= PT or CT primary / PT or CT secondary
• M
= value of the data point from Table 39
data
For example, consider the following capture:
• PT primary = 13.8 kV
• PT secondary = 120 V
• CT primary = 100 A
• CT secondary = 5 A
• Delta voltage mode (line-to-line)
• Capture type = 2
You would multiply each data point by the following factor to
correctly display the waveform:
( )
= N – 1 + N
block
•
M 2
( )
max rms
• •
------------------------------------- -
N
t
R
max
Publication 1404-UM001D-EN-E - October 2004
Advanced Features 8-5
datapoint_this_read
M
data