Communications Errors Caused By Intermodulation; Serial Master Station Input/Output Data - Omron WT30-CA2M Operation Manual

Wireless System Design Considerations
Antenna Separation
Distance
Test Confirmation
2-3-2

Communications Errors Caused by Intermodulation

2-3-3

Serial Master Station Input/Output Data

Intermodulation
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Channel 51
f - (f - f ) = Channel 1
1 2 1
Radio wave created
by intermodulation
Do not select the frequencies of radio waves created by intermodulation.
The distance between WT30 Terminals has a large influence on the amount
of interference received. In particular, there may often be cases where Serial
Master Stations are installed relatively closely to each other. Separate the
Antennas for different Serial Master Stations by at least 2 m if possible.
Perform a test to see whether or not the WT30 Terminals are receiving inter-
ference. Use the RSSI (Received Signal Strength Indicator) on both the Serial
Master Station and I/O Slave Station to check the interference.
Communications errors and retry processing may occur due to intermodula-
tion resulting in transmission delays. To eliminate the influence of intermodu-
lation, do not set the wireless channels for WT30 Terminals in every system to
frequencies at regular intervals.
The Serial Master Station's input/output data is cleared by turning OFF the
power. After turning ON the power, an output signal of all zeros (OFF) is sent
to the output of the I/O Slave Stations from the Serial Master Station.
(1) At power OFF:
All I/O data cleared.
Serial Master
Station
W T3
(2) AT power ON:
0-M 01
-F LK
Sends all "0" output signal.
Due to the fundamental nature of radio waves, if two or more waves with different frequencies
are output at exactly the same time, mutual interference will occur between the different
frequencies, and new waves will be generated with frequencies at intervals equal to the intervals
between the output frequencies.
Serial Master Serial Master
Station Station
I/O Slave Station I/O Slave Station
f = Channel 5 f = Channel 9
1 2
I/O Slave
Station
W T3
0-
SI D1
6
Section 2-3
Channel 63
Frequency
f + (f - f ) = Channel 13
2 2 1
Radio wave created
by intermodulation
(3) Output signal: All "0"
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