uphp:functions:f485open
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uphp:functions:f485open [2017/03/27 15:26] jeff created |
uphp:functions:f485open [2021/09/13 05:57] (current) |
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| ======f485open====== | ======f485open====== | ||
| + | |||
| < | < | ||
| - | Open the RS-485 port at the specified baud rate | + | Open the RS-485 port at the specified baud rate and parity |
| ====Description==== | ====Description==== | ||
| - | <well size=" | + | |
| - | <span style=" | + | <well size=" |
| - | < | + | <span style=" |
| - | <span style=" | + | <span style=" |
| - | <span style=" | + | <span style=" |
| - | <span style=" | + | <span style=" |
| - | <span style=" | + | <span style=" |
| - | <span style=" | + | <span style=" |
| + | <span style=" | ||
| </ | </ | ||
| Attempt to open the RS-485 port as a stream, and return the file handle for future operations | Attempt to open the RS-485 port as a stream, and return the file handle for future operations | ||
| - | In order to use the RS-485 port, you need to disable modbus polling | + | In order to use the RS-485 port, you need to disable modbus polling |
| ====Parameters==== | ====Parameters==== | ||
| - | < | ||
| - | < | + | <html><b>< |
| - | ====Return Value==== | + | < |
| - | Upon success it returns a file handle which may be used together with the other file functions that require a handle such as [[fgets()]], | + | |
| - | If the attempt to open the serial port fails it will return 0 | + | ====Return Values==== |
| + | < | ||
| + | |||
| + | The file handle may be used together with the other file functions that require a handle such as [[fgets()]], | ||
| ====Example==== | ====Example==== | ||
| - | **Open the 485 port at 115200 baud with no parity:** | + | |
| + | ===Open the 485 port at 115200 baud with even parity=== | ||
| <code php> | <code php> | ||
| <? | <? | ||
| $fp=f485open(115200, | $fp=f485open(115200, | ||
| - | if (!$fp) { | + | if ($fp) { |
| - | print(" | + | |
| - | } else { | + | |
| $res=fwrite($fp," | $res=fwrite($fp," | ||
| if ($res) { | if ($res) { | ||
| Line 44: | Line 46: | ||
| } | } | ||
| fclose($fp); | fclose($fp); | ||
| + | } else { | ||
| + | print(" | ||
| } | } | ||
| ?> | ?> | ||
| Line 49: | Line 53: | ||
| ====See Also==== | ====See Also==== | ||
| + | |||
| [[how_tos: | [[how_tos: | ||
| + | |||
| + | [[fopen()]] - Open a file for reading or writing | ||
| [[fseropen()]] - Open the serial port at the specified baud rate with optional parameters | [[fseropen()]] - Open the serial port at the specified baud rate with optional parameters | ||
| Line 55: | Line 62: | ||
| [[fsockopen()]] - Open an internet socket connection with optional timeout | [[fsockopen()]] - Open an internet socket connection with optional timeout | ||
| - | [[fopen()]] - Open a file for reading | + | [[fread()]] - Read bytes from a file, stream |
| - | [[fclose()]] - Close a file, stream or socket | + | [[fgets()]] - Return a single line from a file, stream or socket, with optional size limit |
| - | [[feof()]] - Test if no more data is available in a file or stream | + | [[fwrite()]] - Write data to a file, stream |
| - | [[fgets()]] - Return a single line from a file or stream, with optional size limit | + | [[feof()]] - Test if no more data is available in a file, stream |
| - | [[fread()]] - Return | + | [[filesize()]] - Return |
| - | [[fwrite()]] - Write data to a file or stream | + | [[fseek()]] - Position the file pointer in an open file |
| + | |||
| + | [[ftell()]] - Return the current position of a file read/write pointer | ||
| + | |||
| + | [[fclose()]] - Close a file, stream | ||
uphp/functions/f485open.1490628364.txt.gz · Last modified: 2021/09/13 05:56 (external edit)
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