Mitsubishi Electric MELSEC iQ-R Series User Manual page 181

• Pre-defined Layer 2 receive messages
The meaning of the parameters A to D for a receive message is as follows.
Parameter
*2
Layer 2 message n parameter A
*2
Layer 2 message n parameter B
Layer 2 message n parameter C
Layer 2 message n parameter D
*1 Initial value when the CPU module is powered off and on or reset
*2 To disable the message slot, set Layer 2 message n parameters A and B to FFFFH.
Setting data
■Layer 2 message n parameter A, B
Set the 11-bit/29-bit CAN ID of messages to be received in the message slot of the corresponding Layer 2 message.
■Layer 2 message n parameter C, D
Set the filter for the CAN-ID that was set using Layer 2 message n parameters A and B.
If this is set to 00000000H, whether the CAN-ID of a received message matches the CAN-ID set in Layer 2 message n
parameters A and B is verified.
If either bit is turned on, the bit turned on is ignored when verifying whether the CAN-ID of a received message matches the
CAN-ID set in Layer 2 message n parameters A and B.
Ex.
When Layer 2 message 1 parameters A and B are 00000181H, and Layer 2 message 1 parameters C and D are 00000000H
Only receive messages whose CAN-ID is 00000181H are stored in the message slot of Layer 2 message 1 in 'Receive/
Transmit process data' (Un\G10000 to Un\G10293).
Each time data exchange (a, b, c, d) is performed, the upper byte of RTR/new/DLC is cleared by the program.
Frames on the network
'Data exchange request' (Y1)
'Data exchange completed' (X1)
Upper byte of RTR/new/DLC
(Upper byte of Un\G10002)
'Receive/Transmit
process data'
(Un\G10000 to
Un\G10293)
Data byte
(Un\G10003 to Un\G10006)
: Executed by the RJ71CN91
: Executed by the program
Data exchange b: No message is received between completion of data exchange a (the upper byte of RTR/new/DLC cleared)
and data exchange request b; 00H is therefore stored in the upper byte of RTR/new/DLC.
Data exchange c: A data A message is received (a new frame + new data received) between completion of data exchange b
(the upper byte of RTR/new/DLC cleared) and data exchange request c; 03H is therefore stored in the upper byte of RTR/
new/DLC. Data A is stored in the data byte.
Data exchange d: A data B message is received (a new frame + new data received) between completion of data exchange c
(the upper byte of RTR/new/DLC cleared) and data exchange request d, and a data C message and a data D message are
received (new data received) and then the buffer memory area is overwritten (an overflow occurs for data C and data D each);
07H is therefore stored in the upper byte of RTR/new/DLC. Data D, which has been received last, is stored in the data byte.
Description
Reception CAN-ID
Reception ID filter bit mask
Message
CAN-ID = 00000181H
Data A
ON
a b
OFF
ON
OFF
00H 00H 00H
XXH
Data X
Low word
High word
Low word
High word
Message Message
CAN-ID = 00000181H CAN-ID = 00000181H
Data B Data C
c
03H 00H
Data A
*1
Initial value
FFFFH
FFFFH
0000H
0000H
Message
CAN-ID = 00000181H
Data D
d
07H 00H
Data D
APPX
Appendix 2 Buffer Memory
A
179