Lantronix XPort AR, Руководство по интеграции

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2: Description and Specifications
XPort AR Integration Guide 9
XPort AR Block Diagram
The following drawing is a block diagram of the XPort AR showing the relationships of the
components.
Figure 2-2. XPort AR Block Diagram
PCB Interface
Standard Pins (Evaluation Board XP300200K-01)
The XPort AR has 26 electrical pins. There are 20 pins that form two rows of ten. These 20
pins form the standard interface between the XPort AR and the circuit in which it is installed.
These include dedicated serial as well as 11 programmable I/O pins (Configurable Pins, or
CPs). The other group of six pins is for PoE.
The standard signals are 3.3V CMOS logic level but are 5V tolerant. These signals are
typically connected to internal devices, such as a relays, sensors, or UARTs. For prototype
and evaluation work or applications where an external RS-232 interface is required, RS-232
transceivers are available on the XPort AR evaluation board. Optionally, disconnect them
using the jumpers provided if they are not needed.
Note: Typically, after booting up CP pins are in an unstable state for a few seconds.
However, the state of the CP pins in the XPort-AR is initially high-impedance, suitable
for an input. To use a CP pin as an output, the pin may be biased high or low with a
resistor to +V or ground so it will be "defined" as either 1 or 0 during this initial time.