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Information
Wireless Communication
Type of wireless communication used
●An ISM frequency band from 2,400 MHz to 2,483.5 MHz is used.
●Physical layers (PHY) and media access layers (MAC) formulated
according to IEEE802.15.4 are used.
●The 14 channels of communication frequencies shown below can be
selected. If the interference by peripheral wireless devices is strong,
communication can sometimes be improved by changing the channel.
2400MHz ～2483.5MH ｚ
2
2MHz(at 250kbps)
Channel
12
8MHz(at 1Mbps)
2410MHz
Radio wave status and temperature Indicated using RF utility
●RSSI （Receive Signal Strength Indicator）
This indicator indicates the signal intensity. If the indicator is greater
than 0, radio waves can be transmitted in the relevant environment.
This indicator does not take the effects of interfering waves into
consideration, but can be used as a reference to determine the
intensity of the signal received by the wireless unit connected to the
user system. For example, if the user system is running, this
indicator decreases the longer the communication distance becomes.
By using this indicator, you can estimate how far a signal can be
transmitted in the current environment.
●LQI （Link Quality Indication）
This indicator is calculated based on the intensity of the signal and
noise interference. If this indicator is greater than 0, communication
can be performed in the relevant environment. Unlike RSSI, the
effects of interfering waves are taken into consideration. Therefore,
this indicator is affected by the used frequency band and communication
speed.
For example, if the signal is affected by other wireless devices even
though RSSl is large, LQI decreases. This can sometimes be improved
by changing the used channel.
●Success
This indicator indicates whether the wireless unit connected to the
user system is correctly receiving the data transmitted from the
wireless unit connected to MINICUBE2. Because data that is not
correctly received is ignored, no malfunction occurs, but the operating
speed of the debugger and programming tool is affected.
Using RF Utility More Flexibly
Performing faster wireless communication
The data transfer speed according to the default RF utility settings is
250kbps. The data transfer speed can be changed to 1 Mbps by changing
the setting below in the RF utility configuration dialog box. However,
because LQI tends to decrease if the speed increases, make sure the
radio wave status is relatively stable before changing the speed to
1 Mbps.
Even if 1 Mbps is specified, the operating speed of the debugger does
not simply quadruple. The data transfer speed for wireless communication
quadruples, but the speed of processing the firmware in the wireless
units and USB communication for MINICUBE2 does not change.
5MHz
)
Channel25
)
2475MHz
●This product uses a spread spectrum method called direct sequence
spread spectrum (DSSS) that is highly resistant to disturbing and
interfering waves.
This method transmits 4-bit data by multiplying the data by
pseudonoise codes and then restores the 4-bit data on the receiving
side as actual data. Due to the used code string, the signal frequency
is spread and less affected by interfering waves in specific frequency
bands.
Bit
0000
11011001110000110101001000101110
1000
11101101100111000011010100100010
0100
00101110110110011100001101010010
：
1111
11001001011000000111011110111000
●Temperature
The wireless units have a temperature sensor that determines the
internal temperature of the wireless unit connected to the user
system. This indicator indicates the internal temperature of the unit,
not the ambient temperature. The guaranteed operating temperature
for the wireless units is -15 ℃ to +70 ℃. The red line shown on the
graph in the RF utility shows this temperature range. Use this product
in the guaranteed operating temperature range.
To change the interval at which to update the graphs, change the below
setting in the configuration dialog box .
Customizing LED color for wireless units
When using the wireless units for the first time, the LEDs on the wireless
units turn on in blue. The color of the LEDs can be changed or the
LEDs can be turned off to reduce current consumption.
The LED color for the wireless unit connected to MINICUBE2 can be
changed by specifying a setting in the RF utility configuration dialog box.
By selecting [Synchronize], the same color is specified for the LED on
the wireless unit connected to the user system.
Code
：
Guaranteed operating
Temperature range
Can be specified in the range
from 100 ms to 1,000 ms.
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