7 Layer 2 Communication Mode (11/29 bit ID)
7.3 [BFM #1270 to #1272] Layer 2 RTR Flags
69
FX
3U
-J1939 User's Manual
1
Introduc
tion
2
Specifi
cations
3
Inst
allati
on
4
Wi
rin
g
5
Al
lo
ca
tion of
Buf
fer
Memor
ies
6
J1939 C
omms
Mode
7
La
ye
r 2
C
omm
uni
cation
M
ode
8
PL
C RUN>
S
TOP
Me
ssag
es
9
Co
mmand
Interface
10
Comm
uni
cation
Setti
ngs
Proc
edure
7.3
[BFM #1270 to #1272] Layer 2 RTR Flags
If the FX
3U
-J1939 is set to Layer 2 communication mode, an incoming RTR message is indicated in the BFM
if the following conditions are satisfied:
• Matching the "CAN-ID n
*1
" of one of the Layer 2 messages
• The message "n
*1
" is configured as a transmit message
• The message "n
*1
" is set to "no auto RTR response" (H6FFF)
*1.
Where "n" is one of the messages 1 to 42.
The bits in the "Layer 2 RTR flags" are updated independently from BFM #20 bit 0.
A bit is set if a valid RTR message has been received. The bit can be evaluated by PLC program and the
required changes to the response message data can be made (BFM #20 bit 0 must be set in order to refresh
the internal data buffer and trigger the transmission). The flag is automatically reset when a message is
transmitted from the message.
BFM No.
Bit No.
Description
Read/Write
BFM #1270
Bit 0
RTR message for Layer 2 message 1 received
R
..…
..…
R
Bit 15
RTR message for Layer 2 message 16 received
R
BFM #1271
Bit 0
RTR message for Layer 2 message 17 received
R
..…
..…
R
Bit 15
RTR message for Layer 2 message 32 received
R
BFM #1272
Bit 0
RTR message for Layer 2 message 33 received
R
..…
..…
R
Bit 9
RTR message for Layer 2 message 42 received
R
Bit 10
Not Used
-
..…
Bit 15
