OG_MU1-RIK_v20e Circuit Design, Inc.
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OPERATION GUIDE
The MU1-RS2 is not optimized from the point of view of physical functionality for embedding in final products. When
designing systems that use the RS232C interface, we recommend that you refer to the circuit diagram of the
MU1-RS2 given in this operation guide, and implement the interface part in your user system.
When using the MU1-RS2 without further modification, ground the unit from the MU-1 leg nearest the antenna (the
leg on the soldered side) to the case. Moreover, determine the position and number of grounds through testing.
In systems where a non-directional antenna is required, it is important that the antennas of the transmitting station
and target stations stand vertically in order to exploit communication performance to the maximum. If the planes of
polarisation of the radio waves do not match, receive sensitivity may drop significantly.
Note that if, for reasons peculiar to the equipment, the antenna must be inside the case, communication
performance will be very significantly degraded when handled in the following ways, since these methods
contravene antenna theory. It is the responsibility of the user to test performance thoroughly when designing
equipment.
1. Putting the antenna inside a metal case
2. Wrapping the antenna around the circuit board
3. Locating the antenna beside the ground pattern of the circuit board
4. Fitting the antenna inside by bending it
5. Cutting the antenna to make it shorter
The antenna provided with the MU-1 is a 1/4
λ
whip antenna. Whip antennas are antennas that substitute the ground
as one end of a dipole antenna. For this reason the ground has a very important meaning. Although the main unit of
the MU-1 has the function of a ground, in order to exploit its performance fully, connect it to the largest possible
ground pattern when mounting the MU-1 on your circuit board.
In addition, in the case of two way communication between fixed stations, inclining the whip antenna of the MU-1
forwards may increase its communication range. Carry out tests in the specific environment of use.
The MU1-RS2 is a product that uses an RS232C interface to interface with external equipment. If the MU1-RS2 is
used embedded in a final product, the regulatory compliance assessment in accordance with the R&TTE Directive
depends on the final product. Regulatory compliance assessment should be carried out on the responsibility of the
manufacturer of the final product.
For details of the CE mark, refer to the MU-1 Operation Guide.
)
Point:
The MU-1 radio modem has passed the regulatory compliance assessment in accordance with R&TTE Directive
EN1999/5/EC as a stand-alone product, and has received the CE mark.
4.1 The Antenna
4.2 Regulatory Compliance
Chapter 4 How to Design a User System
