Mitsubishi FX3U-USB-BD User Manual page 607

FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (FX
5.4.13 Sending sum result <BFM #15>
Initial value: 0
This buffer stores the value of the check sum added to the send data.
The sum check target range and check sum calculation method are as shown below.
Sum check target range and check sum calculation method
(Example)
Header
S
T
0 A
X
02 30 41
H H H
30 +41 +31
H H
The sum of the data including the terminators but not the first header (first one byte only) is calculated, the
least significant byte of the calculation result is converted into ASCII code, and the data is sent and received.
The ASCII data is arranged in the order of "upper digit, lower digit".
5.4.14 Receiving sum result <BFM #16>
Initial value: 0
This buffer stores the sum check value of the received data.
If the check sum value added to the received data is different from the receiving sum result, "receiving sum
check error" occurs.
The sum check target range and check sum calculation method are the same as those shown in "5.4.13
Sending sum result" above.
5.4.15 Time from CS ON to sending start <BFM #20>
Set value: 0 to 32767 (× 10 ms)
Initial value: 0 ms
This buffer sets the time between when the sending enable (CS) signal is set to ON until the 232IF actually
starts to send.
When "control line not provided" is specified, this buffer sets the time after the sending command is given until
sending starts.
Set proper time according to the modem, etc.
5.4.16 Time from actual sending completion to RS OFF <BFM #21>
Set value: 0 to 32767 (× 10 ms)
Initial value: 0 ms
This buffer sets the time between when the 232IF completes sending until RS signal turns OFF and the
sending complete flag (BFM #28, b0) turns ON.
Set proper time according to the modem, etc.
-232IF)
2N
Terminator Check sum
E
T
1 2 5 F 5 2
X
31 32 35 46 03 35 32
H H H H H H H
Target range
+32 +35 +
H H H
46 +03 =152
H H H
5 Creating Programs
5.4 Buffer Memory (BFM)
A
B
C
D
E
F
G
H
I
Apx.
G-27