Rs232_Read_Data - Scanlab RTC6 PCIe Board Installation And Operation Manual

Ctrl Command rs232_read_data
Function Reads a value from the input buffer of the RS-232 interface, see
"RS-232 Interface", page
RS232Data = rs232_read_data()
Call
Result As an unsigned 32-bit value.
Bit #0
(LSB)
...
Bit #7
Bit #8
Bit #9
...
Bit #15
Bit #16
...
Bit #23
Bit #24
...
Bit #31
Comments • The RS-232 interface is internally is read in internally asynchronously (one character at
a time). If this character is new, then it is stored in a 256-character ring buffer. From
there, it can be transferred to the user program by rs232_read_data (asynchronously
to reading).
• Byte #0
• Byte #1
• Byte #2
still have not been read by the user program. If no unread characters are present
(byte #2 = 0), then the most recently read character is transferred with "new bit" = 0.
• Byte #3
corresponding number of characters were overwritten and therefore irretrievably lost).
Important: To reset the overflow counter, you must call rs232_read_data
correspondingly often!
• Example: return value 459098 = 0x0007015A = (0, 7, 1, 90) means:
character 90 ('Z') has been read and is new (1), 7 additional characters remain to be
read, the buffer has been never overrun (0).
RTC6 boards
Doc. Rev. 1.0.21 en-US
10 RTC6 Commands
288.
Next (not yet read by the user program) value of the input buffer.
"New" bit:
= 1: The value is new (has not been previously read).
= 0: The value is old (has been already read once
by rs232_read_data).
0.
Number of further (not yet read) characters.
Number of buffer overruns.
(Bit #0...Bit #7) returns only one character from the current reading position.
(Bit #8) indicates if the character has already been read by the user program.
(Bit #16...Bit #23) indicates the number of characters in the input buffer that
(Bit #24...Bit #31) indicates the number of overruns of the input buffer (a
Chapter 9.2.3
595