NAiS FP Series, User Manual

Page: 171 / 326

FP
Σ
Communication Function 2 General-purpose Serial Communication
9 - 4
Outline of operation
To send data to and receive it from an external device using the general-purpose serial
communication function, the “Data transmission” and “Data reception” functions
described below are used. The F159 (MTRN) instruction and the “Reception done” flag
are used in these operations, to transfer data between the FP
Σ
and an external device.
Data transmission
Data to be output is stored in the data register used as the transmission buffer (DT), and
when the F159 (MTRN) instruction is executed, the data is output from the COM. port.
Data writing
Device with
RS232C port
Data register (DT)
FP
Σ
Data transmission using
F159(MTRN) instruction
The end code specified by the system register is
automatically added to the data that has been
sent.
The maximum volume of data that can be sent is
2,048 bytes.
Figure 163: FP
Σ
Data transmission
Data reception
Input data from the COM. port is stored in the received buffer specified by the system
register, and the “Reception done” flag goes on. Data can be received whenever the
“Reception done” flag is off.
FP
Σ
Data register (DT)
Reception done
flag: on
Data receiving
Device with
RS232C port
When data is received, the “Reception done” flag
is controlled by the F159 (MTRN) instruction.
No end code is included in the stored data.
The maximum volume of data that can be received
is 4,096 bytes.
Figure 164: FP
Σ
Data reception