NAiS FP Series, User Manual

Page: 175 / 326

FP
Σ
Communication Function 2 General-purpose Serial Communication
9 - 8
9.2 Overview of Communication with External Devices
This section explains about the communication “data transmission and data reception”
with external devices.
Communication with external device is handled through the data register.
9.2.1 Data Transmission to External Device
Overview of 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.
FP
Σ
Data register (DT)
Data writing
Received data
Device with
RS232C port
Transmitted data
Data transmission using
F159 (MTRN) instruction
Figure 168: FP
Σ
Overview of data transmission
Data table for transmission (transmission buffer)
Data table before transmission
When transmission begins: K8
When transmission ends: K0
Data is transmitted in order
from the low order byte.
DT101 H42(B)
DT102 H44(D)
DT103 H46(F)
DT104 H48(H)
DT100 K8
H41(A)
H43(C)
H45(E)
H47(G)
Figure 169: FP
Σ
Data table for transmission (transmission buffer)