RFD21733 Datasheet, PDF (38/76 Pages) List of Unclassifed Manufacturers – Compliance Approved 2.4 GHz RF Transceiver Modules with Built-In RFDP8 Application Protocol

© Copyright, RF Digital
7/10/2011 1:40 AM
Patents Pending
RoHS CE • ESTI
RFD21733 • FCC • IC
RFD21743 • FCC
Approved & Certified
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RFDP8
RF Module
RFD21733
RFD21735
RFD21737
RFD21738
RFD21739
RFDP8
RFDANT
RFD21742
RFD21743
RFD21772
RFD21773
KEYFOBs
Mode 7 – Switch Receiver with Logic Output (20ms hang-time) (Network)
RFDANTModule Pin Label
Pin # Pin #
2
13 +V
1
10 GND
5
16 Mode Select 0
6
17 Mode Select 1
7
3 Mode Select 2
8
4 Learn / Status
9
5 OUT1
10
6 OUT2
11
7 OUT3
Direction
Input
Input
Input
Input
Input
I/O
Output
Output
Output
Function
+V Power
Ground
Tie to +V
Tie to +V
Tie to +V
Pulse high through a 220 ohm series resistor to enter learn mode.
LED Learn Status Output. Must be pulled to ground through a 47k
resistor and must have series a resistor.
Active high switch output #1, 20 millisecond hang-time.
Active high switch output #2, 20 millisecond hang-time.
Active high switch output #3, 20 millisecond hang-time.
Fast Switch Latency
The RF Modules and RFDANTs with their patent pending RFDP8 interference tolerant protocol have fast
response times. When using a Mode 0 or 1 transmitter and a Mode 4, 5, 6 or 7 receiver, from the time the
transmitter switch input goes high, the receiver output will go high as fast as 5 milliseconds later. It might take as
long as 12mS, but most of the time it is closer to the 5mS time frame.
In Mode 4, Mode 5, Mode 6 and Mode 7, the Module or RFDANT is always in switch receiving mode.
The receiver drives its outputs to match the values received in a packet from a transmitter. This allows up to 8
possible (2³) combinations on the receiver’s outputs.
The term Hang-Time means the period the output will stay high after it has been turned on. It will stay on for the
duration of the hang time, waiting on another packet to be received, if no other packet is received it will go low
after the hang-time period. If a packet is received within the hang-time period it will continue to stay high again for
that period of the hang-time setting (either 20mS or 500mS). If repetitive packages are received within the hang-
time window then the output which was high, will continue to stay high as long as that same input is kept high at
the transmitting radio or Serial transmitter which sent the packet.
Hang time is a trade-off between off-time-latency and resiliency to packet loss. With all RF systems sometimes a
packet will be lost, especially as the distance between the transmitter and the receiver grows. If an output is
connected to a relay driver, packet loss will result in chattering on the relay, which will not have good results. The
500ms hang time is perfect for applications like a keyless entry system or a garage door opener.
For faster switching to the “all off” state, the 20ms hang time is preferred. Since a transmitter sends new data
every 15ms, the time delay to turn off all outputs is only 5ms more than to update the outputs to a different state
where at least one of them is still driven high.
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