Siemens SIMATIC PN/J1939 LINK - 4.5 Control and status information

Functions
4.5 Control and status information
SIMATIC PN/J1939 LINK
Operating Instructions, 12/2018, A5E45307564-AA
25
4.5
Control and status information
Controller information
The following control information is cyclically transmitted from the S7 controller to
PN/J1939 LINK:
Table 4- 3 Structure of the control information in the PROFINET IO data (from S7 controller to
PN/J1939 LINK, 1 byte)
Bit
Meaning
Value
Note
7 to 1
Reserved
0
--
Value must be "0"
0 Control bit 0 No CAN commu-
nication
The CAN controller should be in the "OFF" state.
1 CAN communica-
tion active
The CAN controller should be in the "ON" state.
Status information
The following status information is cyclically transmitted from PN/J1939 LINK to the
S7 controller:
Table 4- 4 Structure of the status information in the PROFINET IO data (from PN/J1939 LINK to
S7 controller, 1 byte)
Bit
Meaning
Possible values
Note
7 to 2
Reserved
--
--
--
1 to 0 State of the
CAN con-
troller
0
OFF
When specified accordingly by the S7 controller.
1 Bus off Error counter
1)
has exceeded the specified thresh-
old or PN/J1939 LINK takes more than 2 seconds
to synchronize to the CAN bus.
As a result, the PN/J1939 LINK no longer
sends/receives packets.
2 Error passive Error counter
1)
has reached the specified threshold.
PN/J1939 LINK continues to send / receive pack-
ets.
3 Error active Error counter
1)
is below a specified threshold.
This is the normal state. Everything is okay.
1) The error counters customary in CAN and their associated thresholds are internal functions that are
not visible to the user.
Note
For values made up of multiple b
its, the first bit is the MSB and the last bit is the LSB.
Example: Bit 1
to 0 = "2" means that bit 0 = "0" and bit 1 = "1".