Allen-Bradley Powermonitor 3000 User Manual page 172

8-22 Advanced Features
Publication 1404-UM001D-EN-E - October 2004
• Capture clear status: Read-only bitfield that indicates which
capture numbers are clear. Bit 0 (LSB) corresponds to capture 1,
bit 1 to capture 2 and so on. For each bit, 1 indicates clear, 0
indicates not clear.
• Capture ready status: read-only bitfield that indicates which
capture numbers contain captures that are ready to read. Same
bit correspondence as above. For each bit, 1 indicates the
capture is ready, 0 indicates no capture or not yet ready.
Block Number
The block number and the total number of data reads required to read
an entire capture depend on the communications option. The range is
1 to 70 for DeviceNet and 1 to 28 for all other communications
options.
Read-Back Mode
The data client uses the indexed read method to read transient
capture data. The readback mode options are:
• Auto-increment all channels: successive reads of Table A.45
increment through all remaining blocks of the current channel,
increment through all remaining channels and wrap back to the
original channel.
• Auto-increment current channel: successive reads of the results
table will increment through all remaining blocks of the current
channel only.
• Manual increment: each write of Table A.45 specifies the
channel and block to be read in the next read of Table A.46.
Successive reads of the results table return the same block of
data each time if no read-back select write is done.
As with other indexed reads, DeviceNet and Ethernet optional
communications support only manual increment read-back mode so
that the client must write a read-back select message before each read
of the results table. For all other communications options,
auto-increment all channels or auto-increment current channel
read-back mode will provide the highest communications throughput.
Table A.46 comprises the transient capture results. This read-only
table comprises 29 (DeviceNet) or 59 (all other communications
options) integer elements:
• Capture timestamp: in three elements using the standard
timestamp format except the year is omitted
• Capture number: in the range 1 to 6