PicoQuant GmbH HydraHarp 400 Software V. 3.0.0.1
Udev
For automated setting of the device file permissions with udev you have to add an entry to the set of rules files
that are contained in /etc/udev/rules.d. Udev processes these files in alphabetical order. The default file
is usually called 50-udev.rules. Don't change this file as it could be overwritten when you upgrade udev.
Instead, put your custom rule for the HydraHarp in a separate file. The contents of this file for the handling of
the current HydraHarp 400 models should be:
ATTR{idVendor}=="0d0e", ATTR{idProduct}=="0004", MODE="666"
ATTR{idVendor}=="0d0e", ATTR{idProduct}=="0009", MODE="666"
A suitable rules file HydraHarp.rules is provided in the folder Linux/udev on the distribution media. You can
simply copy it to the /etc/udev/rules.d folder. The install script in the same distribution media folder does
just this. Note that the name of the rules file is important. Each time a device is detected by the udev system,
the files are read in alphabetical order, line by line, until a match is found. Note that different distributions may
use different rule file names for various categories. For instance, Ubuntu organizes the rules into further files:
20-names.rules, 40-permissions.rules, and 60-symlinks.rules. In Fedora they are not separated
by those categories, as you can see by studying 50-udev.rules. Instead of editing the existing files, it is
therefore usually recommended to put all of your modifications in a separate file like 10-udev.rules or 10-
local.rules. The low number at the beginning of the file name ensures it will be processed before the
default file. However, later rules that are more general (applying to a whole class of devices) may later override
the desired acecss rights. This is the case for USB devices handled through Libusb. It is therefore important
that you use a rules file for the HydraHarp that gets evaluated after the general case. The default naming
HydraHarp400.rules most likely ensures this but if you see problems you may want to check.
Note that there are different udev implementations with different command sets. On some distributions you
must reboot to activate changes, on others you can reload rule changes and restart udev with these
commands:
# udevcontrol reload_rules
# udevstart
Limitations
As noted above, when running under Linux, the HydraHarp software uses Libusb. However, the older version
0.1 of Libusb has an internal limitation of the block size it can handle in one transfer. Therefore, you may
observe lower USB throughput than under Windows. The throughput limitation of Libusb 0.1 can be lifted by
the combination of Libusb 1.0 and the compatibility layer Libusb-Compat that is installed by default on all recent
Linux distributions.
Another limitation is the current implementation of Wine's viewer for chm help files. You may observe some
glitches when using the online help facility.
Finally, please note that running the HydraHarp software under Linux with Wine is an experimental feature that
cannot be covered by regular product support.
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All information given in this manual is reliable to our best knowledge. However, no responsibility is assumed for possible inaccuracies or
omissions. Specifications and external appearance are subject to change without notice.
PicoQuant GmbH
Unternehmen für optoelektronische Forschung und Entwicklung
Rudower Chaussee 29 (IGZ), 12489 Berlin, Germany
Telephone: +49 / (0)30 / 6392 6929
Fax: +49 / (0)30 / 6392 6561
e-mail: info@picoquant.com
WWW: http://www.picoquant.com
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