Application and Installation Guide EMCP 4 SCADA Data Links
©2013 Caterpillar
All rights reserved. Page 52
B8 10 09 01 3E 16 00 00 00 00 00 00 00 00 00 00 00 00 00 00 F5 09 FF 00 0D C3
00 04
B4 10 09 01 3E 16 00 00 00 00 00 00 00 00 00 00 00 00 00 00 F5 09 FF 00 0C 83
00 05
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
00 06
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
00 07
Notice that the last byte (actually the last 2 bytes) is sequential, and indicates the log entry number. This
value is zero based, so the number goes from zero to nineteen ($00 to $13). The other quick observation
is that a sequence of all FF’s indicates that the log entry is empty. In this case, if you refer to Figure 7-7,
there are only 6 events total in the entire log. Therefore, the other 14 entries (log entries 7-20) will be
blank.
NOTE: Events as read over Modbus are, in general, not in the same order as the events viewed on the
EMCP display! In this case, the events happen to populate the first 6 log entries, but this may not always
be the case. For example, if you were to use the Caterpillar Service Tool to Clear an individual event, the
remaining 5 events might populate log entries 1, 2, 4, 5, and 6. And as we will see next, the 6 events we
see above are not in the same order as the 6 events viewed on the EMCP display.
Now we again refer to Appendix A to decode each individual log entry. Let’s look at entry #1 ($00) in
detail. First we’ll number the registers; for consistency with Appendix A (and Application and Installation
Guide), we will number them as offsets from the starting register. (Note that the first byte transmitted is
the high byte of register offset zero, and the last byte transmitted is the low byte of offset 13.)
Offset #: 0 1 2 3 4 5 6
Data:
B0 10 09 01 3E 16 00 00 00 00 00 00 00 00
(ctd)
Offset #: 7 8 9 10 11 12 13
Data:
00 00 00 00 00 00 F5 09 FF 01 F4 FF 00 00
Register Offset 2-0
= Last Timestamp: B0 10 09 01 3E 16
Note that the Byte column indicates, again, the byte offset from the start of this 3-register pair. So
offset 5 is the least significant byte (the “last” byte).
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