Measurement Computing UL for NI LabVIEW - Manual (Page 94)

Universal Library Virtual Instruments (VIs) Serial VIs
Serial VIs
RS485.VI
Sets the direction of RS-485 communications port buffers..
Summary:
Input: BoardNum [U32] - The board number assigned when installed with InstaCal. Can
be 0 to 100.
Transmit [I32] - Enable (1) or disable (0) the transmit RS-485 line driver.
Receive [I32] - Enable (1) or disable (0) the receive RS-485 buffer.
BoardNum [U32] - The board number assigned when installed with InstaCal. Can
be 0 to 100.
Output: ErrCode [I32] - Error code. See ErrMsg.VI
Arguments:
BoardNum The number associated with the board when it was installed with the InstaCal
configuration program. BoardNum may be 0 to 99.
Transmit Set to enabled (1) or disabled (0). The transmit RS-485 line driver is turned on.
Data written to the RS-485 UART chip is transmitted to the cable connected to that
port.
Receive Set to enabled (1) or disabled (0). The receive RS-485 buffer is turned on. Data
present on the cable connected to the RS-485 port is received by the UART chip.
ErrCode Error code from the Universal Library. Zero if no error occurred. Use the ErrMsg
VI to convert ErrCode into a readable string.
Notes:
You can simultaneously enable or disable the transmit and receive buffers. If both are enabled, data written to
the port is also received by the port. For a complete discussion of RS485 network construction and
communication, refer to the CIO-COM485 User's Manual (
www.mccdaq.com/PDFmanuals/cio-com485.pdf ).
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