9. GPIO Interface

Configurable Pins

The xPico has eight pins (CP1-8) that you can configure for General Purpose I/O
(GPIO).
Note: You can also configure the pins for serial port control lines, such as har dware
control, modem control (CTS, RTS, DTR, and DCD), and diagnostic outputs to LED,
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 eight pins independently and in any combination.
The initial directions (input/output) and active levels (active low or hig h) at boot up
can also be configured through 77FE, for example, by using DeviceInstal ler.
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.
The protocol supports up to 32 GPIO for future products.
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.
xPico User Guide 62