Bfm #2 - Mitsubishi Electric MELSEC FX Series User Manual

FX communication
Command 〈BFM #1〉
10.2.3
Bit
b0 Send/receive enable (ER ON)
b1 Send command
b2 Receive completion reset command
b3 Error reset
BFM #1 gives the command for send/receive and the status information reset command to the
232IF.
1 ) b0 (send/receive enable)
While b0 is turned on, the 232IF can send and receive data.
The contents of the following setting items are determined on the rising edge of b0. Make
sure to set the contents using the TO instruction before setting b0 to "ON".
• BFM #0
• BFMs #9 and #8
• BFMs #11 and #10
On the rising edge of b0, the error occurrence (BFM #28 b3) and the error code (BFM #29)
are cleared.
2 ) b1 (send command)
On the rising edge of b1, the contents of the send buffers (BFMs # 1001 to #1256) are sent to
the counterpart equipment up to the send byte count (BFM #1000).
When send is completed, the send completion status (BFM #28 b0) is set. BFM #28 b0 is
automatically reset when the next send command (b1) is given.
When b1 is given, the contents of the following setting items are determined.
• BFMs #5 and #4
• BFMs #7 and #6
3 ) b2 (receive completion reset command)
When b2 is set to "ON", the following items are cleared.
• BFM #28 b1

• BFM #2000

• BFMs #2001 to #2256 (receive buffers)
When receive is completed, b2 should be set to "ON" to clear the receive completion status
(BFM #28 b1). If BFM #28 b1 is not reset, the next data cannot be received.
When b2 is set to "ON", the contents of the following setting items are determined.
• BFMs #9 and #8
• BFMs #11 and #10
In the RS-232C interlink connection mode (BFM #0 b9=1, b8=1), b2 functions as the receive
continuation command to receive data exceeding the receive upper limit byte count (BFM
#2), and clears the following items.
• BFM #28 b4
• BFM #2000
• BFMs #2001 to #2256 (receive buffers)
• BFMs #2257 to #2271 (spare receive buffers)
When b2 is set to "ON", the request to send (RS) signal is automatically set to "ON" also.
4 ) b3 (error reset)
When b3 is set to "ON", the error occurrence status (BFM #28 b3) and error code (BFM #29)
are cleared.
Description
(communication format)
(receive header)
(receive terminator)
(send header)
(send terminator)
(receive completion)
(receive byte count)
(receive header)
(receive terminator)
(receive suspended)
(receive byte count)
FX -232IF 10
2N
10-8