Справочник Пользователя для National Instruments NI PCIe-8255R
© National Instruments Corporation
11
NI PCIe-8255R User Manual
references for the parameters you can set for the NI-IMAQ I/O device
in the Read/Write control. To locate the information, search for
in the Read/Write control. To locate the information, search for
"NI-IMAQ I/O"
in LabVIEW Help.
Specifications
These specifications are typical at 25 °C, unless otherwise stated.
Power Requirements
IEEE 1394 bus power
1
........................... 18 W, maximum
(shared by both ports)
Isolated supply
2
...................................... 5 VDC to 30 VDC
Camera interface
3
................................... IEEE 1394b, compatible with
IEEE 1394a cameras
TTL Inputs and Outputs
Digital logic levels
TTL Inputs
Number of channels ............................... 2
Maximum pulse rate............................... 2 MHz
Minimum pulse detected ........................ 500 ns
Power-on state........................................ Input (high-impedance)
61.9 k
Ω pull-up to 5V
1
The bus power specification assumes that power is provided to the NI 8255R device from the host computer power supply via
the ATX power connector. If power is not supplied through the ATX power connector, camera power is supplied by the PCIe
bus and should be limited to 3 W, shared by both ports.
bus and should be limited to 3 W, shared by both ports.
2
Do not draw more than 100 mA from 30 V isolated outputs. Do not draw more than 50 mA from 5 V isolated outputs.
3
To connect an IEEE 1394a camera to the NI 8255R, you will need a 6-pin to 9-pin cable or a 6-pin to 9-pin adapter.
Level
Minimum
Maximum
Input low voltage (V
IL
)
0 V
0.5 V
Input high voltage (V
IH
)
2.2 V
5 V
Output low voltage (V
OL
), at 5 mA
—
0.4 V
Output high voltage (V
OH
), at 5 mA
2.4 V
—