Number Of Remaining Send Data <Bfm #13; Number Of Receive Buffers <Bfm #14; Send Sum Result <Bfm #15; Receive Sum Result <Bfm #16 - Mitsubishi Electric MELSEC FX Series User Manual

FX communication
10.2.11 Number of Remaining Send Data <BFM #13>
Saved value: 0 to 512 (when buffer data length is 16 bits)
The send byte count (BFM #1000) reduced by the number of data actually sent is during
transmission.
10.2.12 Number of Receive Buffers <BFM #14>
Saved value: 0 to 256
The number of buffers which have actually received data is saved in turn with regard to the
receive buffers BFM #2001 to #2256 and the spare receive buffers BFM #2257 to #2271 for
interlink connection mode.
10.2.13 Send Sum Result <BFM #15>
Initial value:
The check sum value added to the send data is saved.
The sum check target range and the calculation method are shown below.
Note; Sum check target range and calculation method
Example:
Header
S
T
0 A 1
X
02 H 30 H 41 H 31 H 32 H 35 H
Target range
30 H +41 H +31 H +32 H +35 H +
46 H +03 H =152 H
The total value including the terminator and excluding the header (1st byte of the header only) is
calculated. Then, the lower 1 byte is converted into the ASCII code, and sent or received. The
data converted into the ASCII code is placed in the order of upper digit and lower digit.
10.2.14 Receive Sum Result <BFM #16>
Initial value:
The sum check value of the receive data is saved.
When the check sum added to the receive data is different from the receive sum result, "receive
sum check error" occurs.
The sum check target range and the calculation method are equivalent to those for the send sum
result described above.
0 to 256 (when buffer data length is 8 bits)
+15 (for spare receive buffers)
0
Terminator Check sum
E
T
2 5 F 5 2
X
46 H 03 H 35 H 32 H
0
FX -232IF 10
2N
10
10-11