Manual USB-DIO24-CTR6
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USB Connector
The USB connector is a Type B connector and mates with the cable provided. The USB port
provides communication signals along with +5 VDC power. The board can be powered from
the USB port or, if needed for higher current applications, an external power supply can be
used.
LED
The LED on the front of the enclosure is used to indicate power and data transmissions.
When the LED is in an illuminated steady green state, this signifies that the board is
successfully connected to the computer and has been detected and configured by the
operating system. When the LED flashes continuously, this signifies that there is data being
transmitted over the USB bus.
DC Power Jack (Optional)
This is an option for high current applications when more current is needed than what your
computer can provide on the USB port (typically 500 mA). The DC jack has a 2.00mm post
on board and is designed to be used with the regulated 5VDC AC/DC external power supply
that ships with this option. When using external power, switch the jumper located near the
USB connector to VEXT, otherwise when the jumper is in the VUSB position current is
drawn from the USB port (please consult the option selection map for a visual reference).
50 Pin Box Header
The 50 pin box header has standard 0.100" spacing between pins and is keyed to prevent
improper connections. It can be used with standard IDC type ribbon cables or optionally
available screw terminal boards, some of which plug directly into the box header.
Pull-Up / Pull-Down Configuration Jumpers
The 24 bits are divided into four ports: two 8-bit ports (Port A, Port B), and two 4-bit ports
(Port CLo, Port CHi). Each port can be configured independently via onboard jumpers for
pull-up or pull-down, via 10Kohm resistor packs, or no bias, by removing the jumper.
Pull-ups are very common for dry-contact monitoring, while pull-downs prevent the activation
of external inputs and devices during the power-up and reset sequences, before software
can take over. However, due to the 10K resistor packs, any un-used input will not have
suppressed cross-talk. For pull-ups (most common), install these jumpers in the PULLUP
position. For pull-downs, install these jumpers in the PULLDOWN position. For neither,
remove these jumpers. The board ships from the factory with all ports configured with pull-
ups.
Vccio
There are two Vccio levels available on this board. They are 5V (CMOS) and 3.3V (LVTTL).
Vccio applies to all DIO, counter/timer, and external control signals on the connector. Install
the jumper in the desired Vccio position. The board ships from the factory configured for
+5V (CMOS) operation.
