User Manual

13
to the Receiver/ Decoder module. The main functions of the Receiver/Decoder
module are to process the RF signal from the transmitter through the signal
processing circuits, consisting of the band-pass filter, RF amplifier, mixer, IF
amplifier, demodulator, error detection, error correction circuits, and decoder in
order to generate a control command sent to the Relay module to drive the
corresponding relay.
The Relay element is the interface of the Remote Controller to a crane or other
mechanical device. The wiring between the relay contact outputs and the control
circuit (or control box) of the crane or mechanical device can be arranged by the
user.
2-3 Error detection/Error correction by software
F25 system employs the theory of "Error-Control Coding" used on Computer
system, and incorporates the "Control Data Code" and the principle of "Error
detection/Error correction" of Hamming Distance to edit and complete the "Code
Word" was so-called "Hamming Code" which may ensure the control data with
accuracy in process of transmission, and also equip with function of automatic
"Error detection/Error correction" to make sure the safety in operation of F25
system remote control.
2-3-1 Data Stream
As shown as below, before the receiver’s relays output to control the equipment’s
movement, the data including SYNC, ID-CODE, COMMAND and SUM must be
checked twice to further make sure, so the data transmission becomes more safe
and reliable.
TOTAL DATA LENGTH= 144 bits
2-3-2 Hamming Code
ID-CODE COMMAND SUM
SYNC SYNC
SYNC
character 16 bits
Security ID-CODE
48 bits with HAMMING
ENCODED
Action commands 72
Bits with HAMMING
ENCODED
Check SUM
8 bits with
HAMMING
ENCODED