OG_MU-4-434_v10e Circuit Design, Inc.
23
OPERATION GUIDE
4.4.4 Mode setting
When the MODE terminal is at High level
The MU-4 is set to the command mode irrespective of the setting in the mode register. The recommended operation
mode of the MU-4 is the command mode. When setting the MODE terminal to Low to switch to other modes, preset
the mode register.
When the MODE terminal is at Low level
1. In the command mode if the ‘@MD TX’ command is issued, the MU-4 mode register is set to ‘TX’, which is the
text mode. Issuing the ESC code returns from the text mode to the command mode.
2. In the command mode if the ‘@MD BI’ command is issued, the MU-4 mode register is set to ‘BI’, which is the
binary mode. To switch from the binary mode to the command mode, turn off the power supply of the MU-4
briefly or reset the hardware.
If the BI mode is fixed in the EEPROM using the command option ‘/W’, the MU-4 cannot be set to the command
mode without initializing it.
To initialize the MU-4, set the INI terminal to Low and turn on the power, and after turning off the power briefly,
set the INI terminal to High and turn on the power again.
3. By setting the MODE terminal to High level, the MU-4 can be set to the command mode whatever the setting in
the MU-4 mode register (irrespective of the current mode).
Mode relationship diagram
* BI:
Binary mode
CD:
Command mode
TX:
Text mode
* The brackets ( ) in the diagram indicate use of an RS232C driver. When using RS232C communication software on
a PC, the DTR line is always at H level and the MODE terminal is at L level.
M
O
D
E
t
er
m
in
a
l l
e
ve
l
High
Low
Low
@MDTX
MODE
terminal
Low
@MDCD
MODE
terminal
Low
@MDBI
MODE
terminal
MODE
terminal
H
igh
MODE
terminal
H
igh
MODE
terminal
H
igh
Command mode
Binary mode
Text mode
Command mode
@MDTX
@MDBI
1
, Reset (
RST terminal ) *
1
2
, Initialize (
INI terminal
)
*2
*
1: When the mode is set in the RAM
*2: When the mode is fixed in the EEPROM
Mode Register
BI
CD
TX
1, Issue the ESC code
2, Reset (RST terminal ) *1
3, Initialize (
INI terminal
)
*2
