CIRCUIT DESIGN SLR-434M User manual

OPERATION GUIDE
OG_SLR-434M_v10e Circuit Design, Inc.
Embedded low power radio modem
SLR-434M
Smart RF modem
Operation Guide
Version 1.0 (Jan. 2018)
Circuit Design, Inc.
7557-1 Hotaka, Azumino, Nagano, Japan
Tel: [phone]
Fax: [phone]
e-mail: [e-mail]
http://www.circuitdesign.jp

OPERATION GUIDE
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Contents
1. OVERVIEW ......................................................................................................................................... 3
2. FEATURES AND APPLICATIONS ...................................................................................................... 3
3. SPECIFICATIONS............................................................................................................................... 4
4. PART NAMES AND FUNCTIONS ....................................................................................................... 5
5. CONNECTION EXAMPLES FOR DIO TERMINALS .......................................................................... 8
6. APPEARANCE .................................................................................................................................... 9
7. COMMUNICATION FREQUENCY TABLE........................................................................................ 10
8. UART PORT COMMUNICATION SETTINGS....................................................................................11
9. SERIAL COMMUNICATION COMMANDS ....................................................................................... 12

OPERATION GUIDE
OG_SLR-434M_v10e Circuit Design, Inc.
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1. Overview
The SLR-434M smart RF modem is a compact, easy to use, wireless modular RF modem for
embedding in other equipment.
In addition to conventional FSK mode communication, it also comes with a LoRa mode for ultra
long distance communication and low bit rate. With its superior receive sensitivity using LoRa
modulation, it achieves both specific low power output, with a line of sight communication range
of more than 10 kilometers.
Connection to an external microcomputer or a PC via a UART and our proprietary command
system fostered in the industry make it possible for you to easily transmit/receive data.
Also you can control up to 8 contacts.
2. Features and applications
Features
RED compliant (Plan)
Ultra long distance communication using the LoRa mode
Enhanced resistant to city noise and longer range compared with our earlier products
Select between FSK mode and LoRa mode
UART interface
Control of 8 contacts
Low power consumption enables battery powered operation
Compact size
Applications
Data transfer inside buildings, air conditioning control
Debris avalanche monitoring for debris barriers
Water level monitoring for river dams, opening and closing of water gates
Paddy field temperature and water level monitoring
Monitoring and control of greenhouse temperature and humidity
Transmission of sensor data from underground or inside manholes
Measurement and observation of the state of tunnels and bridges
Monitoring the state of electric fences
Monitoring the state of animal traps
Other IoT applications

OPERATION GUIDE
OG_SLR-434M_v10e Circuit Design, Inc.
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3. Specifications
*All values are when the antenna connector is the 50 Ω terminal.
*Unless otherwise indicated, specified values are at a temperature of 25 °C ± 5 °C.
Item Specification
Applicable standard EN 300 220
Frequency channels 433.075 MHz to 434.7750 MHz (12.5 KHz step, 137 channels)
Frequency deviation ± 2 ppm or less
Antenna power 10 mW or less
Communication
method Half-duplex or one-way
Radio wave format F1D
Modulation*1LoRa or Binary FSK
Radio communication
speed
15 to 245 bps (Real speed using LoRa, depends on the spreading
factor)
4800 bps (FSK)
Receiver spurious
radiation -54 dBm or less
Receive sensitivity*2-133 dBm (LoRa 128 chip), -115 dBm or less (FSK),
PER 1% with the user data of 45 bytes or less
Carrier sensing
threshold -96 dBm (LoRa)
Operating temperature
range -30 to +70°C
Storage temperature
range -30 to +80°C
Recommended
operating voltage range 3.5 to 5.0 V
Warranted operating
voltage range 3.3 to 5.5 V
Operating current Tx: 29 mA (Typ) Rx: 17 mA (Typ) (Supply power = 5 V)
Antenna provided 1/4λ whip antenna (L=170 mm, gain 2.14 dBi or less)
Antenna connector SMA
Interface UART port
External dimensions 40 × 29 × 6.2 mm (±0.4) (Not including the antenna and
projections)
Weight 13 g
Soldering conditions Hand soldering
Soldering iron temp.: 350°C within 3 seconds
Note:
*1: When using the LoRa mode and moving around, the impact of the Doppler effect may make
communication impossible.
*2: Receive sensitivity performance is affected by the power supply and surrounding noise levels (floor noise
level). The approximate minimum level at which reception is possible is noise level +10 dB for FSK and -10
dB for LoRa. (Example: When the floor noise level is -110 dBm, reception is possible with FSK to about -
100 dBm and with LoRa to about -120 dBm). You can check the floor noise level with the @RA command
and the evaluation application (air monitor).

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4. Part Names and Functions
Names
and
functions
I/O Content Internal equivalent circuit
TXD O A UART serial communication
terminal.
It sets the device and transmits
and receives data.
(Communication conditions:
19.2 kbps, Bits =8, Parity =
none, Stop = 1)
Serial data
Transmitter
RXD I Serial data
Receiver
RTS O
The UART control terminal.
When RTS = “Hi”, do not input
data.
Hardware flow
control output
terminal
CTS I
The UART control terminal.
When CTS = “Hi”, data is not
output.
(Set it to “Lo”.)
Hardware flow
control input
terminal
MODE I (Reserved)
Nothing should be connected to this terminal.
VCC
GND
TX-LED
RX-LED
DIO4
DIO5
DIO6
DIO7
DIO8
TXD
RXD
RTS
CTS
MODE
INI
RESET
DIO1
DIO2
DIO3
Antenna connector

OPERATION GUIDE
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INI I
With the power on, setting this terminal to
“Lo” for 3 s or more resets and restarts the
unit, and if the wireless communication mode
is binary mode, it enters the command mode.
For details about the wireless communication
mode, refer to the operation guide "SLR-434
Serial Communication".
Normally, when set to the wireless
communication mode, the settings are saved
automatically and are used as the initial
values next time the power is switched on.
However, after setting the binary mode, it is
not possible to receive commands, therefore
it is necessary to perform this task to return to
the command mode. When this task is
performed, "LORA CMD MODE" or "FSK CMD
MODE" is output from the TXD terminal after the
device restarts.
After reset and restart, the device is initialized
to the setting value saved by adding ‘/W’ to
commands such as chip number, frequency
channel.
RESET I
The CPU reset terminal (Lo active).
After reset and restart, the device is initialized
to the setting value saved by adding ‘/W’ to
commands such as chip number, frequency
channel.
DIO1 I/O Digital I/O pin 1. Input/output settings can be
made with commands.
DIO2 I/O Digital I/O pin 2. Input/output settings can be
made with commands.
DIO3
I/O
Digital I/O pin 3. Input/output
settings can be
made with
commands. DIO3
and DIO4 cannot
be set individually.
DIO4 Digital I/O pin 4.
DIO5
I/O
Digital I/O pin 5.
Input/output
settings can be
made with
commands.
DIO5 to DIO8
cannot be set
individually.
DIO6 Digital I/O pin 6.
DIO7 Digital I/O pin 7.
DIO8 Digital I/O pin 8.

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RX-LED O
The reception monitor LED connection
terminal (Lo Active).
When a radio wave communication signal is
received, this terminal changes to “Lo” for
about 0.1 s.
TX-LED O
The transmission monitor LED connection
terminal (Lo Active).
When a radio wave communication signal is
sent, this terminal changes to “Lo”.
GND The ground terminal.
VCC The power supply terminal. Connect to a
stabilized DC+3.3 V to +5.5 V power supply.
Antenna
Connector I/O The connection pin for the antenna.
※The voltage range of the output terminal is 0 to Vcc [V].
Use the input terminal within the range Hi = 2.0 to Vcc [V], Lo = 0 to 0.6 [V]

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5. Connection examples for DIO terminals
<When using the DIO terminals as input ports and connecting switches>
The DIO terminals are internally pulled-down and can be operated by connecting switches
between the DIO terminals and the VCC terminal as shown below (SW1 & SW2). The SW3 in the
circuit below shows an example of connecting a switch to the GND side with the signal level
inverted via a transistor.
Using long wiring between the DIO terminal and the switch may cause malfunction due to noise.
In that case, take measures such as externally pulling down with a resistor of a few to tens of kΩ.
<When using the DIO terminals as output ports and connecting loads>
The output current at the DIO terminal should be 5 mA or less.
Pay attention to the voltage drop due to the 330 Ω resistor inside the SLR-434M (see the
equivalent circuit above.)
A load of a few mA, such as LED, can be directly
driven as below.
Connecting a transistor or FET
Connecting a Photo Tr or PhotoMOS relay Connecting a relay

OPERATION GUIDE
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6. Appearance
Note: When designing circuit boards, take care to ensure space for the SMA connector
dimensions and screw fixture for connecting the antenna. (If the underside of the connector is
also the surface of the substrate, provide a notch or the like)
PCB

OPERATION GUIDE
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7. Communication frequency table
The frequencies used for radio communication are the 137 channels in the 434 MHz band shown in
the table below.
Channel Frequency Channel Frequency Channel Frequency
NO. HEX (MHz) NO. HEX (MHz) NO. HEX (MHz)
0 00 433.0750 34 22 433.5000 68 44 433.9250
1 01 433.0875 35 23 433.5125 69 45 433.9375
2 02 433.1000 36 24 433.5250 70 46 433.9500
3 03 433.1125 37 25 433.5375 71 47 433.9625
4 04 433.1250 38 26 433.5500 72 48 433.9750
5 05 433.1375 39 27 433.5625 73 49 433.9875
6 06 433.1500 40 28 433.5750 74 4A 434.0000
7 07 433.1625 41 29 433.5875 75 4B 434.0125
8 08 433.1750 42 2A 433.6000 76 4C 434.0250
9 09 433.1875 43 2B 433.6125 77 4D 434.0375
10 0A 433.2000 44 2C 433.6250 78 4E 434.0500
11 0B 433.2125 45 2D 433.6375 79 4F 434.0625
12 0C 433.2250 46 2E 433.6500 80 50 434.0750
13 0D 433.2375 47 2F 433.6625 81 51 434.0875
14 0E 433.2500 48 30 433.6750 82 52 434.1000
15 0F 433.2625 49 31 433.6875 83 53 434.1125
16 10 433.2750 50 32 433.7000 84 54 434.1250
17 11 433.2875 51 33 433.7125 85 55 434.1375
18 12 433.3000 52 34 433.7250 86 56 434.1500
19 13 433.3125 53 35 433.7375 87 57 434.1625
20 14 433.3250 54 36 433.7500 88 58 434.1750
21 15 433.3375 55 37 433.7625 89 59 434.1875
22 16 433.3500 56 38 433.7750 90 5A 434.2000
23 17 433.3625 57 39 433.7875 91 5B 434.2125
24 18 433.3750 58 3A 433.8000 92 5C 434.2250
25 19 433.3875 59 3B 433.8125 93 5D 434.2375
26 1A 433.4000 60 3C 433.8250 94 5E 434.2500
27 1B 433.4125 61 3D 433.8375 95 5F 434.2625
28 1C 433.4250 62 3E 433.8500 96 60 434.2750
29 1D 433.4375 63 3F 433.8625 97 61 434.2875
30 1E 433.4500 64 40 433.8750 98 62 434.3000
31 1F 433.4625 65 41 433.8875 99 63 434.3125
32 20 433.4750 66 42 433.9000 100 64 434.3250
33 21 433.4875 67 43 433.9125 101 65 434.3375