In this section, you can find functions and subroutines frequently used for controlling I/O devices. For more detailed information, please refer to the next section.
| All functions must be used with brackets. |
Command | Description | ||
Communication | Function | OpenPort | Opens the serial port. |
Function | ClosePort | Closes the serial port. | |
Function | SendByte | Sends byte data with the selected port. | |
Function | SendString | Sends string data with the selected port. | |
Function | ReceiveByte | Receives data with the selected port. | |
Function | GetCommStatus | Checks the selected station’s communication status. | |
Subroutine | EnableDriver | Controls the selected station’s communication. | |
| - EnableDriver() command only supports MODBUS RTU (XpanelDesigner V2.53). - GetCommStatus() command can only be used in XpanelDesigner V2.53 or above. |
PortNo., BaudRate, Parity, and Stop Bit use predefined constants. Refer to the table shown below for details.
Constant Name | Value | Usage |
_COM232_ | 0 | Uses COM1 port as RS232C mode. |
_COM422_ | 1 | Uses COM1 port as RS422 mode. |
_COM485_ | 2 | Uses COM1 port as RS485 mode. |
_COMAUX_ | 3 | Uses COM2 port as RS232C mode. |
_BPS300_ |
| 300 bps |
_BPS600_ |
| 600bps |
_BPS1200_ |
| 1200bps |
_BPS2400_ |
| 2400bps |
_BPS4800_ |
| 4800bps |
_BPS9600_ |
| 9600bps |
_BPS19200_ |
| 19200bps |
_BPS38400_ |
| 38400bps |
_BPS56000_ |
| 56000bps |
_BPS57600_ |
| 57600bps |
_BPS115200_ |
| 115200bps |
_BPS128000_ |
| 128000bps |
_BPS256000_ |
| 256000bps |
_PARITY_NONE_ |
| NO PARITY BIT |
_PARITY_EVEN_ |
| EVEN PARITY |
_PARITY_ODD_ |
| ODD PARITY |
_PARITY_MARK_ |
| MARK PARITY |
_PARITY_SPACE_ |
| SPACE PARITY |
_STOPBIT_ONE_ |
| 1 STOP BIT |
_STOPBIT_TWO_ |
| 2 STOP BITS |
_STOPBIT_ONE5_ |
| 1.5 STOP BIT |
OpenPort | Opens the serial port. |
Function | n=OpenPort(PortNo., BaudRate, Parity, Data Bit, Stop Bit) |
Description | PortNo. (use predefined constant, _COMxxx_) BaudRate (use predefined constant, _BPSxxx_) Parity (use predefined constant, _PARITY_xxx_) Data Bit (7 or 8) Stop Bit (use predefined constant, _STOPBIT_xxx_) This function opens the assigned serial port. You cannot use this function if the port has already been opened. Once you opened the COM port with the script, it has to be closed with ClosePort() function. When an error occurs during the port opening, the script will return 0. If the port is successfully opened, the script will return the value other than 0. |
Example | Opens COM1 port with following options; RS485, 19200bps, No Parity, Data Bit 8, Stop Bit 1. OpenPort(_COM485_, _BPS19200_, _PARITY_NONE_, 8, _STOPBIT_ONE_); |
ClosePort | Closes the serial port. |
Function | n=ClosePort(PortNo.) |
Description | PortNo. (use predefined constant, _COMxxx_) Closes the assigned serial port which is opened by the OpenPort() function. When an error occurs during the port closing, the script will return 0. If the port is successfully closed, the script will return the value other than 0. |
Example | Closes COM1 port. ClosePort(_COM485_); |
SendByte | Sends byte data with the selected port. |
Function | n=SendByte(PortNo., Data) |
Description | PortNo. (use predefined constant, _COMxxx_) Data (0~255) This function is used when you wish to transmit a data with the COM port which is opened by OpenPort() function. Data must be a byte data in the range of 0(0x00) to 255(0xFF). If the data is greater than 255(0xFF), only the lower byte will be transmitted. For example, if you assign Data with 0x1234, only 0x34 will be transmitted. OpenPort() function must be used before the execution of SendByte() function. If an error occurs during the data transmission, the script will return 0. If the data is successfully transmitted, the script will return the value other than 0. |
Example | Transmits byte data “2” through COM1 port which uses RS485 communication. SendByte(_COM485_, 2); |
SendString | Sends string data with the selected port. |
Function | SendString(PortNo., Data) |
Description | PortNo. (use predefined constant, _COMxxx_) Data (Enter the String Tag or “String”) This function is used when you wish to transmit a data with the COM port which is opened by OpenPort() function. The Data must be assigned with string tag or string data. If you use the string data, it must be used with double quotation marks. (“ “) OpenPort() function must be used before the execution of SendString() function. If an error occurs during the data transmission, the script will return 0. If the data is successfully transmitted, the script will return the value other than 0. |
Example | Transmits byte data “TEXT” through COM1 port which uses RS485 communication. SendString(_COM485_, “TEXT”); |
ReceiveByte | Receives data with the selected port. |
Function | ReceiveByte(PortNo., Data) |
Description | PortNo. (use predefined constant, _COMxxx_) Data (0~255) This function is used when you wish to receive a data with the COM port which is opened by OpenPort() function. Once you receive the data successfully, the Data (0~255) will be stored in the variable. If there is no received data until the timeout, the script will return 256. OpenPort() function must be used before the execution of ReceiveByte() function. |
Example | Receives byte data through the COM1 port which uses RS485 communication. Saves the received data at the variable ‘RxData’. VAR RxData; OpenPort(_COM485_, _BPS19200_, _PARITY_NONE_, 8, _STOPBIT_ONE_); RxData = RecieveByte(_COM485_, 1000); If(RxData < 256) { } …… |
GetCommStatus | Checks the selected station’s communication status. |
Function | GetCommStatus(“DeviceName”, “StationName”) |
Description | Returns the status of the assigned DeviceName ‘s StationName.. If the communication is normal, the script will return 1. If there is an error at the communication, the script will return 0. |
Example | Checks the communication status of the device “PLC”’s station “STATION”. CommStatus = GetCommStatus(“PLC”,”STATION); |
EnableDriver | Controls the selected station’s communication. |
Subroutine | EnableDriver(“DeviceName”, “StationName”, Enable/Disable) |
Description | Controls the communication of the assigned DeviceName ‘s StationName. Enter 1 to Enable/Disable to enable the communication. Enter 0 to disable the communication. This function only supports MODBUS RTU at XpanelDesigner V2.52. |
Example | Enables the station “STATION “ of “MODBUS” device. EnableDriver(“MODBUS”, “STATION”, 1); |