Mitsubishi Electric FX3U-CAN, Руководство пользователя

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9 CAN Layer 2 Mode
9.3 Pre-defined Layer 2 Message Configuration
173
FX
3U
-CAN User's Manual
1
Introduc
tion
2
Specifi
cations
3
Inst
allati
on
4
Wi
rin
g
5
Introduc
tion of
Functions
6
All
ocation of
B
uff
er
Memor
ies
7
Interface and D
evice P
rofile
(40
5 mode)
8
Lift Appl
icati
on
P
ro
file
(417 M
ode)
9
CAN
Layer 2
Mode
10
Comm
and
Interface
9.3.2 Pre-defined Layer 2 receive messages
This subsection describes parameters A to D for the receive message.
1. Parameter A and B for each Layer 2 message
Set the source CAN ID of the received message to parameter A and B. CAN-ID is as follows, corresponding
to the function mode to be used.
When Layer 2 message number is not used, set HFFFF to both parameter A and B.
→ For function mode, refer to Section 6.5
2. Parameter C and D for each Layer 2 message
Set the filter for the ID set in parameter A and B. If the filter is set to H00000000, incoming messages are
checked for an exact match with the ID set in parameter A and B. Any bit set in the filter will be omitted when
comparing received IDs with the ID set in parameter A and B.
Example 1:
Layer 2 message 1 parameter A/B = H00000181
Layer 2 message 1 parameter C/D = H00000000
BFM #100 to #106 store received messages with the CAN-ID H181 only. Relation between received CAN
message, BFM #20 bit 0 and "RTR/new/DLC" high byte is shown below.
The flags "RTR/new/DLC" are cleared by PLC program after . They remain H00 after , because there
was no message stored between and . The first received CAN message that matches parameter A/B
and C/D is stored into the internal buffers, and as this is the only message between and , the high byte
value is set to H03. The high byte value H07 after shows that the buffer was overwritten at least once (in
this example two times) since . The data bytes in the BFM are the data received with the last message.
Note
In this example, it is expected that the PLC program resets the “RTR/new/DLC” flags after reading the data at
, , and .
Parameter Description Initial Value
Layer 2 message number parameter A Reception CAN-ID low word HFFFF
Layer 2 message number parameter B Reception CAN-ID high word HFFFF
Layer 2 message number parameter C Reception ID filter bit mask low word H0000
Layer 2 message number parameter D Reception ID filter bit mask high word H0000
Function Mode Description
11 bit CAN-ID Layer 2 Mode Store CAN-ID in the 11 bits, bit 0 to 10, in the parameters A and B by 32 bit instructions.
29 bit CAN-ID Layer 2 Mode Store CAN-ID in the 29 bits, bit 0 to 28, in the parameters A and B by 32 bit instructions.
CAN bus
BFM #20
bit 0
RTR/new/DLC
high byte
Message
H0181
Message
H0181
Message
H0181
Message
H0181
H00 (no new data
between and )
H03 (new frame + data
between and )
H07 (new frame + data
and overflow between
and )
H00 Hxx