Measurement Computing UL for NI LabVIEW - Manual (Page 73)

Universal Library Virtual Instruments (VIs) Digital I/O VIs
DCfgPort.VI
Configures a digital port as Input or Output. This mode is primarily for use with 82C55 chips and 8536 chips.
See the board user's manual for details of chip operation.
Summary:
Inputs: BoardNum [U32] - The board number assigned when installed with InstaCal. Can
be 0 to 100.
PortNum [I32] - Specifies which digital I/O port to configure.
Direction [TF]- DIGITALOUT or DIGITALIN
Outputs: BoardNum [U32] - The board number assigned when installed with InstaCal. Can
be 0 to 100. Can be used to pass BoardNum parameter to another VI.
ErrCode [I32] - Error code. See ErrMsg.VI
Arguments:
BoardNum The board number associated with a board when it was installed with InstaCal.
PortNum The specified port must be configurable.
For many boards, AUXPORT is not configurable. However, some later boards do
require that the AUXPORT be configured using DCfgPort.VI or DCfgBit.VI.
Please see board details for more information.
The table below shows which ports and bit numbers are in which 82C55 and 8536
digital chips. The CIO-DIO192 supports eight 82C55 chips—the most available on
a single board. The PCI-INT32 support two 8536 chips— the most available on a
single board.
Mnemonic Bit # 8255 Chip # Chip Address 8536 Chip # Chip Address
FIRSTPORTA 0 - 7 1A Base + 0 1A Base + 0
FIRSTPORTB 8 - 15 1B 1B
FIRSTPORTCL 16 - 19 1CL 1C
FIRSTPORTCH 20 - 23 1CH Not present
SECONDPORTA 24 - 31 2A Base + 4 2A Base + 4
SECONDPORTB 32 - 39 2B 2B
SECONDPORTCL 40 - 43 2CL 2C
SECONDPORTCH 44 - 47 2CH No port C High in 8536 chips
and so on, to the last chip on the board as: THIRDPORTx, FOURTHPORTx, FIFTHPORTx, SIXTHPORTx,
SEVENTHPORTx and...
EIGHTHPORTA 168 - 175 8A Base + 28
EIGHTHPORTB 176 - 183 8B
EIGHTHPORTCL 184 - 187 8CL
EIGHTHPORTCH 188 - 191 8CH
Direction DIGITALOUT (True) or DIGITALIN (False - default) configures an entire eight-
or four-bit port for output or input.
BoardNum (Out) The board number used when installed with InstaCal. This parameter can be used
to serialize VIs such that this VI precedes the next VI whose BoardNum is attached
to this output.
Notes
Using this function will reset all ports on a chip configured for output to a zero state. This means that if you
set an output value on
FIRSTPORTA and then change the configuration on FIRSTPORTB from OUTPUT to INPUT ,
the output value at FIRSTPORTA will be all zeros. You can, however, set the configuration on SECONDPORTX
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