Yaskawa VS-616G5 Modbus Plus Communication Card - Manual (Page 78)

10-2 Application Notes
Register Types
The Modbus Plus Interface board allows the MB+ network access to a drive’s internal data
registers. The two different types of data registers vary in the method they use to access the
drive’s internal memory. The two different types are as follows:
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High Speed Registers - (0001-000F, F000-F00F) allow direct access to the drive’s
memory via dual port RAM or shared memory. This allows for very quick access to the
drive’s memory. The high speed registers are shown in italics in Appendix A.
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Serial Registers - (0020-050D, F100-F10F) allow access to the drive’s memory via a
serial interface. Data is transmitted to and received from the drive’s memory serially,
which is considerably slower than high speed registers.
Through-put
The following graphs compare the time it takes to complete the given read or write operation for a
given number of data registers or block size.
High Speed Register Through-put
16.5
17
17.5
18
18.5
19
19.5
20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
block size
read
write