Allocation Of Buffer Memories (Bfm's); Bfm List - Mitsubishi Electric MELSEC FX Series User Manual

FX communication

10.2 Allocation of Buffer Memories (BFM's)

The RS-232C interface block FX
via buffer memories BFMs (16-bit RAM memories) in the 232IF.
FNC78 (FROM) and FNC79 (TO) instructions are used to read and write the buffer memories.
10.2.1

BFM List

BFM
No.
#0 Communication format
#1 Command
#2 Receive upper limit byte count
#3
Receive time-out time
Send header, lower 2 bytes
#4
#5
Send header, upper 2 bytes
Send terminator, lower 2 bytes
#6
#7
Send terminator, upper 2 bytes
#8 Receive header, lower 2 bytes
#9
Receive header, upper 2 bytes
Receive terminator, lower 2
bytes
#10
#11
Receive terminator, upper 2
bytes
Receive suspension waiting
#12
time (in interlink connection)
Number of remaining send
#13
data
#14 Number of receive buffers
#15 Send sum result
#16 Receive sum result
Note : "W : For write" can be used for read also. Undefined BFM Nos. are not allowed to be used
in program.
*1 : Spare buffers used in the interlink connection mode.
-232IF(232IF) transmits data with the programmable controller
2N
Name
1 to 512 (when data length is 16
bits)
1 to 256 (when data length is 8
bits)
"0" is treated as "512" or "256".
1 to 32,767 (X10 ms)
"0" eliminates time-out time.
4 bytes max., zero suppression
4 bytes max., zero suppression
4 bytes max., zero suppression
4 bytes max., zero suppression
0 to 32,327 (X10 ms)
0 to 512 (when data length is 16
bits)
0 to 256 (when data length is 8
bits)
0 to 256 + 15 *1
Setting range




FX -232IF 10
2N
R:For read
Initial value W:For
write
0087H W
0 W
0 W
0 W
0 (no header)
W
0
0 (no
terminator) W
0
0 (no header)
W
0
0 (no
terminator) W
0
0 W
0 R
0 R
0 R
0 R
10-2