--- title: System Commands description: Power, status, and configuration commands for the RS-UV3A --- ## TX – Transmit Controls the transmitter. ### Syntax ``` TXn ``` ### Parameters | Value | Description | |-------|-------------| | 0 | Stop transmitting (return to RX) | | 1–5 | Transmit with n-minute timeout | ### Examples ``` TX1 # Transmit, 1 minute max TX3 # Transmit, 3 minute max TX0 # Stop transmitting ``` ### Notes - `TX0` stops TX even if hardware PTT is held - Timeout overrides `TO` setting for this transmission only - If TX is off, radio is in RX mode --- ## PW – TX Power Sets the transmit power level. ### Syntax ``` PWn PW? ``` ### Parameters | Value | Power Level | |-------|-------------| | 0 | Low (~10 mW, 10 dBm) | | 1 | High (~200 mW, 23 dBm) | ### Default 1 (High) ### Examples ``` PW1 # High power PW0 # Low power PW? # Query current setting ``` --- ## TO – Timeout Sets the transmit timeout timer. ### Syntax ``` TOnnn TO? ``` ### Parameters | Parameter | Range | Description | |-----------|-------|-------------| | `nnn` | 000–600 | Timeout in seconds | | | 000 | Disable timeout | ### Default 000 (disabled) ### Examples ``` TO180 # 3 minute timeout TO300 # 5 minute timeout TO000 # No timeout TO? # Query current setting ``` ### Notes - All 3 digits required - When timeout occurs, sends TG message and unkeys - Protects against stuck PTT --- ## TG – Timeout Message Sets the CW message sent when TX times out. ### Syntax ``` TG TG? ``` ### Parameters | Parameter | Description | |-----------|-------------| | `` | Message up to 7 characters | ### Default 'TO' ### Examples ``` TGTIME # Send "TIME" on timeout TGTO # Send "TO" (default) TG? # Query current message ``` --- ## HT – Hang Time Sets TX hang time for repeater applications. ### Syntax ``` HTnnnn HT? ``` ### Parameters | Parameter | Range | Description | |-----------|-------|-------------| | `nnnn` | 0000–5000 | Hang time in milliseconds | ### Default 0000 (no hang time) ### Examples ``` HT1500 # 1.5 second hang time HT2000 # 2 second hang time HT0000 # No hang time HT? # Query current setting ``` ### Notes - All 4 digits required - TX stays keyed for specified time after PTT release - Used with courtesy beep in repeater applications --- ## CO – COR Inhibit Sets the COR (Carrier Operated Relay) inhibit time. ### Syntax ``` COnnnn CO? ``` ### Parameters | Parameter | Range | Description | |-----------|-------|-------------| | `nnnn` | 0000–9999 | Inhibit time in milliseconds | ### Default 0000 ### Examples ``` CO0150 # 150 ms inhibit CO0200 # 200 ms inhibit CO? # Query current setting ``` ### Notes - Prevents COR from going active briefly after TX ends - Avoids squelch noise triggering COR - Useful for packet and repeater applications --- ## CB – Courtesy Beep Sets the courtesy beep for repeater applications. ### Syntax ``` CBn CB? ``` ### Parameters | Value | Beep | |-------|------| | 0 | None | | 1 | Low tone | | 2 | High tone | | 3 | High/low | | 4 | Two tones | ### Default 0 (none) ### Examples ``` CB0 # No beep CB2 # High tone beep CB? # Query current setting ``` ### Notes - Sounds after hang time expires - Signals repeater is ready for next transmission --- ## VX – VOX Enables or disables voice-operated transmit. ### Syntax ``` VXn VX? ``` ### Parameters | Value | Description | |-------|-------------| | 0 | VOX off | | 1 | VOX on | ### Default 0 (off) ### Examples ``` VX1 # Enable VOX VX0 # Disable VOX VX? # Query current setting ``` ### Notes - Pressing PTT disables VOX - Do not use with speaker-mic (RX audio will trigger TX) - Sensitivity set by `VL` command --- ## VL – VOX Level Sets VOX sensitivity. ### Syntax ``` VLn VL? ``` ### Parameters | Value | Sensitivity | |-------|-------------| | 0 | High (most sensitive) | | 1 | Medium | | 2 | Low (least sensitive) | ### Default 1 (Medium) ### Examples ``` VL0 # High sensitivity VL2 # Low sensitivity VL? # Query current setting ``` --- ## BW – Bandwidth Sets the channel bandwidth. ### Syntax ``` BWn BW? ``` ### Parameters | Value | Bandwidth | |-------|-----------| | 0 | 12.5 kHz (narrow) | | 1 | 25 kHz (wide) | ### Default 1 (25 kHz) ### Examples ``` BW1 # 25 kHz (standard) BW0 # 12.5 kHz (narrow) BW? # Query current setting ``` ### Notes - **Requires power cycle to take effect** - Use narrow for crowded bands - Some repeaters require narrow bandwidth --- ## PD – Power Down Controls the transceiver chip power. ### Syntax ``` PDn PD? ``` ### Parameters | Value | Description | |-------|-------------| | 0 | Chip powered down | | 1 | Chip powered on | ### Default 1 (on) ### Examples ``` PD0 # Power down (saves ~70 mA) PD1 # Power up PD? # Query state ``` ### Notes - Reduces current by approximately 70 mA - Radio cannot TX/RX when powered down - Serial commands still work --- ## B1 – Baud Rate 1 Sets the baud rate for serial port 1 (USB/JP1/JP2). ### Syntax ``` B1n B1? ``` ### Parameters | Value | Baud Rate | |-------|-----------| | 0 | 1200 | | 1 | 4800 | | 2 | 9600 | | 3 | 19200 | | 4 | 38400 | | 5 | 57600 | ### Default 3 (19200) ### Examples ``` B13 # Set to 19200 B15 # Set to 57600 B1? # Query current setting ``` ### Notes - **Requires power cycle to take effect** - Reconnect terminal at new baud rate after power cycle --- ## B2 – Baud Rate 2 Sets the baud rate for serial port 2 (DB-9 I/O connector). ### Syntax ``` B2n B2? ``` ### Parameters Same as B1. ### Default 3 (19200) ### Notes - Only applies when `EX1` (serial mode) - **Requires power cycle to take effect** --- ## FW – Firmware Version Reports the current firmware version. ### Syntax ``` FW ``` ### Response ``` FW: 2.4A ``` ### Notes - Query only, no parameters --- ## BL – Bootloader Enters bootloader mode for firmware updates. ### Syntax ``` BL ``` ### Notes - RS-UV3A waits indefinitely for bootloader connection - Power cycle required to exit without updating - See [Firmware Upgrade](/guides/firmware-upgrade/) guide --- ## SS – Signal Strength Reads the current receiver signal strength. ### Syntax ``` SS ``` ### Response ``` SS: -85 ``` Value is in dBm. --- ## SN – Noise Level Reads the current receiver noise level. ### Syntax ``` SN ``` ### Response ``` SN: 1234 ``` ### Notes - Lower values indicate cleaner signal - Raw value, not calibrated --- ## VT – Voltage Reads the operating voltage. ### Syntax ``` VT ``` ### Response ``` VT: 8.5V ``` ### Notes - Reads the 8.5V internal rail - Useful for monitoring power status --- ## TP – Temperature Reads the PCB temperature. ### Syntax ``` TP ``` ### Response ``` TP: 42 ``` Temperature in °C. ### Notes - PCB temperature, not ambient - Will be warmer during TX --- ## BS – Battery Status Legacy command for battery charger status. ### Syntax ``` BS ``` ### Response ``` BS: 0 ``` or ``` BS: 1 ``` ### Notes - RS-UV3A Rev A does not have battery charging - Included for compatibility with older RS-UV3 versions --- ## RR – Register Read Reads an RDA1846S transceiver chip register. **Advanced use.** ### Syntax ``` RRxx ``` ### Parameters | Parameter | Description | |-----------|-------------| | `xx` | Register address in hex | ### Response Returns 16-bit hex value. ### Notes - For advanced debugging only - Register documentation available online for RDA1846S --- ## RS – Register Set Sets an RDA1846S transceiver chip register. **Advanced use.** ### Syntax ``` RSxxyyyy ``` ### Parameters | Parameter | Description | |-----------|-------------| | `xx` | Register address in hex | | `yyyy` | 16-bit value in hex | ### Response ``` OK ``` or no response if failed. ### Notes - Can disrupt radio operation if used incorrectly - For advanced debugging only - Settings may not persist through power cycle