Yaesu VR-5000 Operating Manual page 57

Data Protocol
Serial data is passed via the
57600 bits/sec. All commands sent from the computer to the receiver consist of five-byte
blocks, with up to 200 ms between each byte. The last byte sent in each block is the instruc-
tion opcode, while the first four bytes of each block are arguments: either parameters for
that instruction, or dummy values (required to pad the block out to five bytes):
Each byte sent consists of one start bit, 8 data bits, no parity bit and two stop bits:
Data Byte Format
Start Bit 0 1 2 3 4 5 6 7 Stop Bit Stop Bit
5-Byte Command Structure
Parameter 1 (LCD) Parameter 2 Parameter 3 Parameter 4 Command Data
There are three instruction opcodes for the VR-5000, listed in the table below. Most of
these duplicate menu programming settings or options, or else emulate front panel button
functions. Notice that several instructions require no specific parameters. However, every
Command Block sent to the radio must always consist of five bytes.
The control program you are writing must construct the 5-byte block, by selecting
the appropriate instruction opcode, organizing the parameters, if any, and providing un-
used (dummy) argument bytes for padding the block to its required 5-byte length (the
dummy bytes can contain any value). The resulting five bytes are then sent, opcode last,
from the computer to the VR-5000 CPU via the serial port and
rear panel.
Opcode Command Data
Command Tittel
ON/OFF
Set Frequency
Receiving Mode
Receiver Status
Note 1: F1 ~ F4 = Frequency Digits (HEX),
Example: 439.70 MHz = 02, 9E, ED, D0
Note 2: Receiving Mode/Channel Step Parameter Codes
M1
00 LSB 44 WAM
01 USB 48 WFM
02 CW 84 AM-N
04 AM 88 FM-N
Note 3: Receiver Status
7 6 5 4 3 2 1 0
VR-5000 O
jack on the rear panel of the radio at 4800, 9600, or
Parameters
F1 F2 F3 F4
M1 M2
F1, F2, F3, F4
21 20 Hz 43
02 100 Hz 53
42 500 Hz 63
03 1 kHz 04
S-Meter Data
Squelch Data
M
Opcode
P1 P1= 00: ON, P1 = 80: OFF
P1 P1= 01: MAIN VFO
P1= 31: SUB VFO
P1 P1= 07: MAIN VFO
P1= 37: SUB VFO
E7 S-Meter, Squelch, etc.
M2
5 kHz 05 100 kHz
6.25 kHz 45 500 kHz
9 kHz 14 12.5 kHz
10 kHz 24 20 kHz
0 = Squelch OFF
1 = Squelch ON
Operation
jack on the radio
Comments
Note 1
Note 2
Note 3
34 25 kHz
44 50 kHz
– –
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