XPort User Guide
64
9: GPIO Interface
Configurable Pins
The
XPort
has three pins (CP0-2) that you can configure for General Purpose
I/O (GPIO).
Note:
You can also configure any one of the pins for modem control input
signal (serial port control line) using DeviceInstaller.
You can use these GPIO pins to control devices such as relays, servers, lights,
monitor switches, sensors, and even processes such as data transfer.
You can set the functions for the three pins independently and in any combination.
The initial directions (input/output) and active levels (active low or high) at boot up
can also be configured through 77FE, for example, by using DeviceInstaller.
This chapter describes how the directions, active levels, and states can be
dynamically controlled and probed through special port 77F0.
The configurable pins default configuration is:
Function: General Purpose Input
Active Level: Active Low
Features
TCP and UDP can be used.
Function configuration can be retrieved.
Input or output selection can be retrieved and controlled.
Active low or high selection can be retrieved and controlled.
Active or inactive selection can be retrieved and controlled.
77F0 can be disabled.
Every change of state (active/inactive) requires a command over TCP or UDP, and
thus is not very fast. If you use this port for data transfer, the throughput is low,
usually up to 1 Kbps.
