Camera Operation & Features
23
PixeLINK PL-A780
Document No.: 04646-01
MACHINE VISION CAMERA
SYSTEM GUIDE
Copyright © 2004 PixeLINK
All Rights Reserved
The debounce delay can be adjusted to allow for non-TTL signals to be used. To adjust the
debounce delay for use with analog signals, use the Debounce Delay Adjustment Tool
included with the PixeLINK software. A copy of the application is also available from the
PixeLINK Web Site at
. Look for the tool on the PL-A780 product
page. The tool adjusts the clock frequency used to determine a valid trigger signal. The
trigger detection circuit tests the value of the trigger at each clock tick and will only declare a
trigger event when the trigger signal changes and remains constant for 5 clock cycles. By
varying the clock frequency, the PL-A780 can use either analog trigger generators or digital
TTL type signals. The clock frequency can be set at values ranging from 156 Hz to 10 MHz.
For analog trigger sources, such as the Trigger Accessory included with the Developer’s and
Camera Kits, a clock setting of 100kHz or slower is required. For very clean digital triggers,
the clock can be increased to the maximum 10 MHz. The camera is shipped with the clock
set to 5 MHz.
Table 8 Pinout of the 6-Pin Hirose Connector
Pin Pin Name
Function
Comments
1 POWER
FireWire cable power, 8–30
V DC (typically 12 V)
o
Maximum current available from
this pin is 250 mA.
2 Positive terminal of
optically isolated trigger
input
3 TRIGGER– Negative terminal of
optically isolated trigger
input
o
To initiate a trigger, apply a voltage
of between 5 V and 12 V (4–11 mA)
to the trigger terminals.
o
The optically isolated trigger input
circuit includes an internal 1 k
Ω
series resistor.
o
When using a voltage higher than
12 V, add an external resistor with
adequate power rating.
o
A typical application of the trigger
input is to connect Pin 1 (POWER)
to Pin 2 () and use the
open collector output of an external
position sensor device to complete
the circuit from Pin 3 (TRIGGER–)
to Pin 4 (GROUND).
o
Timing: See Section 8.1 on page
54.
o
PixeLINK API--Refer to the
functions
PxLSetFeature,
PxLGetFeature
4
GROUND
Logic and chassis ground
o
5
GP1
General Purpose Output
(GPO) 1, for strobe
(Pinout as viewed
on the back of the
camera, or at the
solder-end of the
mating connector)
6
GP2
General Purpose Output
(GPO) 2, for strobe
o
Open-collector current sink output
from optical isolator. Provides
current sink to Pin 4 (GROUND)
when GP1/GP2 (as appropriate) is
active.
o
Maximum current is 15 mA.
o
Timing: See Section 8.2 on page 55
o
PixeLINK API--Refer to the
functions
PxLSetFeature,
PxLGetFeature
4.6.3.2 Trigger Connection Examples
The trigger inputs can accept floating signals that aren’t tied to the camera ground.
