T H E M O D E R M - B U S T E C H N O L O Y
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8.7
Finding meters on the M-Bus network
Finding meters on an M-Bus network with the PiiGAB M-Bus 900 can be done with primary
addressing or secondary addressing. If you have many meters with the same primary address
you will get a collision indication. To be able to separate these meters you will need to use to
secondary addressing.
8.7.1
Finding meters via primary address
When using primary addressing a SND_NKE is first sent and if a meter responds a REQ_UD2 is
sent to read out the meter information. Some meter do not like to first get a SND_NKE and
directly after that a REQ_UD2, therefore you can cancel the SND_NKE question. The search will
then take a little longer since a timeout is required between each question.
To make the search more effective you can set the interval of the primary address if you know
that your meters should be within a certain area.
Figure 8-24
8.7.2
Step by step instruction for primary address search
Finding M-Bus meters on the M-Bus loop using primary addressing.
1.
Specify the baud rate on the M-Bus network.
2.
State what type of questions of ”SND_NKE” or ”REQ_UD2” to be used.
3.
State the first and the last primary address for the search.
4.
Click ”Start search”
.
