VR-5000 OPERATING MANUAL 55
CAT Data Protocol
Serial data is passed via the CAT jack on the rear panel of the radio at 4800, 9600, or
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:
CAT Data Byte Format
Start Bit 0 1 2 3 4 5 6 7 Stop Bit Stop Bit
CAT 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 CAT 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 CAT jack on the radio
rear panel.
Opcode Command Data
Command Tittel Parameters Opcode Comments
CAT ON/OFF P1 P1= 00: ON, P1 = 80: OFF
Set Frequency F1 F2 F3 F4 P1 P1= 01: MAIN VFO
P1= 31: SUB VFO Note 1
Receiving Mode M1 M2 P1 P1= 07: MAIN VFO
P1= 37: SUB VFO Note 2
Receiver Status E7 S-Meter, Squelch, etc. Note 3
Note 1: F1 ~ F4 = Frequency Digits (HEX),
Example: 439.70 MHz = 02, 9E, ED, D0
F1, F2, F3, F4
Note 2: Receiving Mode/Channel Step Parameter Codes
M1 M2
00 LSB 44 WAM 21 20 Hz 43 5 kHz 05 100 kHz 34 25 kHz
01 USB 48 WFM 02 100 Hz 53 6.25 kHz 45 500 kHz 44 50 kHz
02 CW 84 AM-N 42 500 Hz 63 9 kHz 14 12.5 kHz – –
04 AM 88 FM-N 03 1 kHz 04 10 kHz 24 20 kHz – –
Note 3: Receiver Status
76543210
S-Meter Data
Squelch Data 0 = Squelch OFF
1 = Squelch ON
CACA
CACA
CA
TT
TT
T Operation
To Next Page
Loading...
Need help?
General
