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RS232 communication protocol
Communication format: 1 start bit, 8 data bits, 1 stop bit, no parity
Baud rate：9600Bps
Communication method: asynchronous half-duplex serial communication
Overview: DVI matrix, HDMI matrix and audio and video matrix all have cascadable RS232 control interface, which can be controlled by a computer or central control host RS232 interface, and use the same protocol to distinguish different devices through prefix and ID code.
Command format：
| Prefix | Device ID | Command word | Data 1 | Data 2 | End word |
| PV | 00~99 | CMD | DATA1 | DATA2 | NT |
Support command list：
| Command word | Data 1 | Data 2 | Description |
| SW | Enter the channel number | Enter the channel number | Video and audio switch at the same time |
| SA | Enter the channel number | Enter the channel number | Audio switching |
| SV | Enter the channel number | Enter the channel number | Video switching |
| VW | 00 | Output channel number | Query the status of the specified output channel |
| VW | 00 | 00 | Query the status of all output channels |
| SF | Preset status number | 00 | Save the current state to the specified preset location |
| RF | Preset status number | 00 | Restore the specified preset state |
| ID | Specify id | 00 | Modify the ID code of the device to the specified ID |
Extended command
Command format：
| Prefix | Device ID | Command word | Data 1 | Data 2 | Data 3 |
| PV | 00~99 | CMD | DATA1 | DATA2 | DATA3 |
| Command word | Data 1 | Data 2 | Data 3 | Description |
| MW | Enter the channel number | Output starting channel number | Output end channel number | Multi-channel video and audio switching at the same time |
| MA | Enter the channel number | Output starting channel number | Output end channel number | Multi-channel audio switching at the same time |
| MV | Enter the channel number | Output starting channel number | Output end channel number | Multi-channel video switching at the same time |
Prefix：
PV：Corresponding to DVI and HDMI matrix
Input channel number: 01~Maximum input channel number: corresponding to the actual input channel.
00：Close the specified output channel.
>Maximum input channel number: invalid, return an error command.
Output channel number: 01~Maximum output channel number: corresponding to the actual output channel.
00: Switch the designated input channel number to all output channel numbers.
>Maximum output channel number: invalid, return an error command.
Preset state number: 01-15: The device supports 15 preset states, which can save video and audio at the same time.
Device ID: 00: General ID. All devices respond to this ID. Please do not use this ID when there are more than two devices controlled by the same serial port; if you don’t know the ID of the current device, you can use the computer serial port to connect to the device separately. Use the universal ID to modify the ID of the device to the specified ID.
01~99：The effective ID of the device。
Specify ID:01～99。
Device return data: if all command data except VW (query status) command is correct, the device will return OK, and if data is wrong, it will return Err;
DVI/HDMI matrix: PV) + the number of input channels + the number of output channels + the video input channel of the first output channel + the audio input channel of the first output channel + the video input channel of the second output channel + the second output The audio input channel of the channel + ... + the video input channel of the largest output channel + the audio input channel of the largest output channel + OK.
For example, the ID code of a DVI/HDMI matrix is 08, and the second input needs to be switched to 5 outputs, the command is: PV08SV0205NT; a 16×16 DVI/HDMI matrix, the ID code is set to 26, you need to change The fifth input is switched to the first to the ninth output, the command is: PV26SV050109, you need to send 9 different codes from 01-09; if you want to switch the third input to all outputs, the command is: PV26SV0300NT.