National Instruments NI 9866, Начало работы

Страница: 6 / 11

Connector Pin Signal Name
7 LIN
8 NC
9 V
SUP
Table 1. Pin Assignments for the NI-9866
Cabling Requirements for the NI 9866
This section deals with cabling specifications, termination resistors, cable lengths,
and the number of LIN nodes that can exist in a system.
Cable Specifications
LIN cables should meet the physical medium requirement of a bus RC time constant
of 5 µs. For detailed formulas for calculating this value, refer to the Line
Characteristics section of the LIN specification. Belden cable (3084A) and other
unterminated CAN/Serial quality cables meet these requirements and should be
suitable for most applications.
Cable Lengths
The maximum allowable cable length is 40 m, per the LIN specification.
Number of LIN Devices
The maximum number of devices on a LIN bus is 16, per the LIN specification.
Termination Resistors
LIN cables require no termination, as nodes are terminated at the transceiver. Slave
nodes typically are pulled up from the LIN bus to VBat with a 30 kΩ resistance and a
serial diode. This termination usually is integrated into the transceiver package. The
master node requires a 1 kΩ resistor and serial diode between the LIN bus and VBat.
On NI-XNET LIN products, master termination is software selectable; you can enable
it in the API with the NI-XNET Session Interface:LIN:Termination property.
ni.com
6
NI-9866 Getting Started