High−level Instructions
3 − 333
Program and operation during reception
Data sent from the external device connected to the COM port will be stored in the data register areas set as
the reception buffer.
Word
(address) 0
Area used for
number of bytes
received
1
2
n
12
2n 2n−1
Area used for storing received data
(the circled numbers indicate the
storing order)
Reception buffer
34
Each time data is received, the amount of data received (number of bytes) is stored as a count in the leading
address of the reception buffer. The initial value is zero.
The data received is stored in order in the reception data storage area beginning from the lower byte of the
second word of the area.
Example:
Reception of the eight characters A, B, C, D, E, F, G, and H (8
bytes of data) from an external device
The reception buffer is DT200 to DT204 in this example.
System register settings are as follows:
− System register 417: K200
− System register 418: K5
DT200
Each time data is received,
the number of bytes received
is stored.
DT201
DT202
DT204
H42
(B)
H41
(A)
H44
(D)
H43
(C)
H48
(H)
H47
(G)
The reception data is
stored in order from the
lower byte.
DT203
H46
(F)
H45
(E)
K8
Reception buffer when
reception is completed
FP2/FP2SH/FP10SH
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