Temporal Performance Of I/O Lines; Introduction - Basler acA2040-55 User Manual

Physical Interface

5.10 Temporal Performance of I/O Lines

This section describes delays ("propagation delays") resulting from the operation of the camera's
input and output lines. For image acquisition, the propagation delays must be added to the delays
described in Chapter 6 on
You will need the information included in this section most likely only if you need microsecond
accuracy when controlling camera operation via I/O lines.
All examples in this section assume that the I/O line inverters are disabled.

5.10.1 Introduction

As indicated in Section 5.2 on
opto-isolated I/O lines

direct-coupled General Purpose I/O (GPIO) lines.

The related electrical characteristics and circuit schematics are given in
Section 5.9.
With regard to use, the two kinds of I/O lines differ mainly in these respects:
The opto-isolated I/O lines have the advantage of being distinctly more robust against EMI

than the GPIO lines.
The propagation delays ("response times") differ between the two kinds of I/O lines.

A propagation delay is the time that elapses between the moment when a signal voltage passes
through the transition threshold and the moment when the related line status changes – or vice
versa (see Figure 46
The following important characteristics are apparent from
The propagation delays for the opto-isolated I/O lines are in most cases longer than for the

GPIO lines. In other words, the opto-isolated I/O lines are usually "slower" than the GPIO lines.
For each analog signal, the rising edge and the falling edge are associated with different

propagation delays. The edge with the shorter propagation delay (the "fast" edge) is indicated
in the figures by an asterisk.
For recommendations for use, see Section on
84
page 109.
page 68, the camera provides two different kinds of I/O lines:
for camera input and Figure 47
page
Section 5.7
for camera output).
Figure 46 and Figure
89.
AW00123409000
through
47:
Basler ace USB 3.0