Siemens SIMATIC PN/J1939 LINK, Руководство по эксплуатации

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Functions
4.1 J1939 protocol
SIMATIC PN/J1939 LINK
Operating Instructions, 12/2018, A5E45307564-AA
17
Address claiming
Addresses for J1939 devices are assigned using the "Address Claiming" procedure. With
"Address Claiming", each J1939 device sends its desired network address and its J1939
name with PGN 60928. If no other device is using this address, the preferred address can be
used. If the address is already in use, the respective devices compare their names. The
name with the lowest numeric value "wins" the conflict and the corresponding device can use
the address.
With PN/J1939 LINK, you can configure whether the device is able to change its network
address (Arbitrary Address Capable). The parameters are set via the corresponding bit of
the device name:
Table 4- 1 Device name - "Arbitrary Address Capable" field (1-bit)
Value Meaning Behavior for address claiming
Bit = 0 PN/J1939 LINK cannot
change its address.
If another device claims the same address with a higher priority,
the PN/J1939 LINK performs the following actions:
•
PN/J1939 LINK sets its address to 254 (Null address).
• PN/J1939 LINK sends the diagnostics alarm "Invalid ad-
dress" to the S7 controller. See Diagnostic messages
(Page 58).
PN/J1939 LINK can no longer participate in J1939 communica-
tion and must be configured with a new J1939 network address.
Bit = 1 PN/J1939 LINK can
change its address.
If another device claims the same address with a higher priority,
the PN/J1939 LINK performs the following actions:
• PN/J1939 LINK increments its current address.
•
PN/J1939 LINK sends the diagnostics alarm "Network ad-
dress changed" to the S7 controller. See Diagnostic mes-
sages (Page 58).
PN/J1939 LINK can continue to participate in J1939 communi-
cation.
After a restart, PN/J1939 LINK uses the "Source Address" con-
figured in the TIA Portal again.
Peer-to-peer and broadcast communications
The J1939 protocol makes it possible to send messages either to all subscribers (broadcast)
on the bus or to individual subscribers at specific addresses (peer-to-peer).