Eaton IQ 150S, User & Installation Manual

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IM02601006E www.eaton.com B-19
IQ 150S/250S B: Modbus Map
• If the meter Returns a Slave Busy Exception, repeat the request.
• If the Window Status is 0xFF, repeat the request.
• If the Window Status is 0, go to step 2b (Verify record index).
NOTES:
• We read the index and window in 1 request to minimize communication time, and to
ensure that the record index matches the data in the data window returned.
• Space in the window after the last specified record (RecordSize x RecordPerWin-
dow) is padded with 0xFF, and can be safely discarded.
b. Verify that the record index incremented by Records Per Window. The record index of the
retrieved window is the index of the first record in the window. This value will increase by
Records Per Window each time the window is read, so it should be 0, N, N x 2, N x 3 . . . for
each window retrieved.
• If the record index matches the expected record index, go to step 2c (Compute next
expected record index).
• If the record index does not match the expected record index, then go to step 1d
(Write the retrieval information), where the record index will be the same as the
expected record index. This will tell the IQ 250S meter to repeat the records you
were expecting.
c. Compute next Expected Record Index.
• If there are no remaining records after the current record window, go to step 3 (Dis-
engage the log).
• Compute the next expected record index by adding Records Per Window, to the cur-
rent expected record index. If this value is greater than the number of records, re-
size the window so it only contains the remaining records and go to step 1d (Write
the retrieval information), where the Records Per Window will be the same as the
remaining records.
3. Disengage the log: write the Log Number (of log being disengaged) to the Log Index and 0 to
the Enable bit [0xC34F, 1 reg].