UART – UART communication block

Block SymbolLicensing group: STANDARD

Function Description
The UART block allows you to read and write data via the Universal Asynchronous Receiver-Transmitter. The port parameter specifies device name. There it is possible to use two name types:

the address of the physical device – Usually /dev/ttyS* for Linux target or COM* for Windows. Replace "*" symbol according to the chosen serial port!
the virtual address – REXYGEN enables the creation of a virtual UART with which you can communicate inside REXYGEN with other blocks supporting UART such as REXLANG, PYTHON, another UART block or Modbus driver. On Linux devices, the virtual port is marked with the prefix pty: (pseudo terminal) and it is possible to connect to it from another application running on the device. On Windows devices, it is possible to use the prefix vcom, which enables communication within REXYGEN. Virtual port examples: pty:/tmp/vslave, vcom:vmaster.

UART communication has several general properties that are set using parameters such as baudrate, parity, databits and stopbits. Each packet that is received or transmitted is assigned a unique ID. The ID of the next packet is always one higher than the ID of the previous packet. Once the maximum ID is reached, the next ID assigned will be 0. The maximum ID value is determined by the maxId parameter. Data is sent with the rising edge of the idTx input.

Inputs

dataTx	Vector reference to transmitted data	Reference
lenTx	Transmitted data length (0 = whole vector) $↓$ 0	Long (I32)
idTx	ID of the transmitted data packet $↓$ 0	Long (I32)
idRxAck	ID of the last processed received data packet $↓$ 0	Long (I32)
WAIT	Transmission suspended flag (data is buffered)	Bool
	on ... The transmitted data is still in the buffer off .. The transmitted data (the entire buffer) is sent
R1	Block reset	Bool

Outputs

dataRx	Vector reference to received data	Reference
lenRx	Received data length $↓$ 0	Long (I32)
idRx	ID of the received data packet $↓$ 0	Long (I32)
idTxAck	ID of the last processed transmitted data packet $↓$ 0	Long (I32)
MORE	Additional data in the receive buffer flag	Bool
status	Internal status indicator	Long (I32)
	0 .... No Error 1 .... Transmit buffer overflow 2 .... Transmit data error 256 .. Received data error -1 ... Failed to open port

Parameters

port	Communication device name	String
baudrate	Baudrate [bis/s] (0 = not set) $↓$ 0 $↑$ 4000000	Long (I32)
parity	Parity	Long (I32)
	0 .... Not set 1 .... No parity 2 .... Odd parity 3 .... Even parity
databits	Number of data bits (0 = not set) $↓$ 0 $↑$ 3	Long (I32)
stopbits	Number of stop bits (0 = not set) $↓$ 0 $↑$ 2	Long (I32)
maxId	Max value used as ID of a packet $↓$ 2 $↑$ 10000000 $⊙$ 4	Long (I32)
maxLen	Maximum length of the received data $↓$ 1 $↑$ 10000000 $⊙$ 64	Long (I32)
nmax	Allocated size of array $↓$ 8 $↑$ 10000000 $⊙$ 256	Long (I32)

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