599 Menlo Drive • # 100 • Rocklin, CA 95765
Sales / Technical Support - Tel: (916) 624-8333 Fax: (916) 624-8003
Web: http://www.parallaxinc.com or http://www.stampsinclass.com • Email: [email protected]
1-27-2000, V1.0 • Mfg. by www.
RFDigital.com
Page
7
RF MODULES
Non-similar mode settings are when the transmitter and receiver have opposite mode settings. For example,
transmitter’s Mode pin is connected to 0V (Switch Mode) and receiver’s Mode pin is connected to +5V (Serial
Mode)..
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NON-SIMILAR COMMUNICATING MODES
Transmitter = Switch Mode
Receiver = Serial Mode
Any logic high (+5V) applied to IN1, IN2, or IN3 of the transmitter can be read out of the RXD serial output
pin of the receiver. While any of the three inputs, IN1, IN2 or IN3 are high, the transmitter will repeatedly
transmit the same byte of information to the receiver. The byte contains IN1, IN2 and IN3 switch input
information, in addition to the status of the 4 address pins of the transmitter. See table below.
IMPORTANT: OUTPUT DATA BITS AND ADDRESS BITS ARE INVERTED
Example:
The transmitter is in switch mode and +5V is applied to ADDR3 and +5V is applied to IN1. With the receiver
in serial mode, the RXD pin will output the following serial byte; 01111100. The LSB, bit position "0" of the
received byte is not used and is always "0". For everywhere a "1" is placed on any transmitter input pin (IN1
– IN3) the receiver will display a "0" in that bit position. For everywhere a "0" or open is applied to any
transmitter input pin the receiver will display a "1" in that bit position. When a transmitter is in switch mode, it
will only transmit when one of the three inputs IN1, IN2 or IN3 are brought to +5V.
OUT1
BIT 7
OUT2
BIT 6
OUT3
BIT 5
ADDR1
BIT 4
ADDR2
BIT 3
ADDR3
BIT 2
ADDR4
BIT 1
0
BIT 0
Transmitter = Switch Mode
Receiver = Switch Mode
Any logic high +5VDC placed on IN1, IN2 or IN3 of the transmitter will be reflected at the receiver’s OUT1,
OUT2 or OUT3, respectively. Logic levels on transmitter and receiver address pins ADDR1 to ADDR4 must
match.
