OG_MU4-RS2IF_v10e Circuit Design, Inc.
11
OPERATION GUIDE
Using the reset command @SR, the MU4-RS2 can be reset to the status when the power was turned on.
The parameters set in the EEPROM remain unchanged.
Reset the unit to the factory default settings if communication with the MU-4 mounted on the MU4-RS2 is not
possible or if you are uncertain of the internal settings.
How to initialize the MU-4
Turn on the power while pressing the initialize button. Then turn the power off and on once again to reset the unit to
the default settings. For details of the default status, refer to the default values for each command in the MU-4
Operation guide.
The MU-4 can also be initialized using the initialize command @IZ.
Status after initializing
The values of the main parameters after initializing are as follows.
1. Link related parameters
User ID: UI = 0000, Group ID: GI = 00, Equipment ID: EI = 01, Destination ID: DI = 01, Channel = 0 channel
2. UART related parameters
Baud rate = 19,200 bps, parity = none, stop bit = 1
3. Parameters related to internal operation
Mode = command
The diagram below is an example of how to connect the MU4-RS2 and the single-chip CPU. Insert an RS232C
transceiver in the CPU signal line.
Since the MU4-RS2 DTR line is connected to the MU-4 MODE terminal, be sure to control the level in accordance
with the MU-4 mode being used.
2
1
VCC
GND
MU-4
λ
/4
Lead antenna
Regulator
+3v
2
3
4
5
6
7
1
8
10
11
12
9
13
14
INI
RXD
TXD
RTS
CTS
MODE
RESET
DI
RF
GND
VCC
AF-MON
DO
TX-LED
RX-LED
+
-
LED1
LED2
LED3
CN1
Power terminal
DC
+3.2v
～
+12v
SW1
Power switch
1
RXD
2
TXD
3
DTR
4
GND
5
DSR
6
RTS
7
CTS
8
9
CN2
D-Sub 9pin
male
SW2
initialize
1
2
RXD
3
TXD
4
DTR
5
GND
6
DSR
7
RTS
8
CTS
9
RS232C
level conversion
RS232C
level conversion
CPU
RXD
TXD
RTS
CTS
Output Port
(Mode control)
Straight cable
User system
MU4-RS2(RS232C interface board + MU-4)
3.3 Initializing
3.2 Resetting
3.4 Connection example
