Here are some questions we are frequently asked
about for iPad charging and syncing
applications. Call us if you have other
questions that we haven't addressed below.
We support the new iPad and all previous models.
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We encounter a lot
of people who say they prefer to (or eventually will) use wireless for syncing. What should people know about wired
(USB) syncing vs. wireless syncing?
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What types of
cables work with the DS-IP-SYNCCHARGE devices?
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How long does
it take to charge 16 iPads using the DS-IP-SYNCCHARGE or DS-IP-PP16 devices?
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How long does
it take to sync 16 iPads to iTunes using the DS-IP-SYNCCHARGE devices?
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Can we use a
Mac mini, G5 or Windows PC to sync to 16 iPads?
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A MacBook has multiple USB ports.
Can you plug in two DS-IP-SYNCCHARGE devices into each port and sync 32
iPads at one time?
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What are the minimum requirements of
the Apple computer to be able to sync?
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How can I find a basic how-to for syncing multiple iPads?
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Can multiple Sync-Charge boards be linked to allow communication with many iPads (50, 100 or more)?
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I have a variety of USB devices that I would like to charge. Is there a universal USB charger?
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Are your USB charging and sync-charge devices Energy Star compliant?
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Do your sync devices work with the new Apple Configurator?
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Can we use Configurator with your sync devices (carts, cabinets, etc.) to work with more than 30 devices at a time?
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Do your USB chargers accurately measure the charge status of the device batteries being charged?
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Why do amps matter when you consider a USB charging (or charge-and-sync) device?
We
encounter a lot of people who say they prefer to
(or eventually will) use wireless for syncing.
What should people know about wired (USB)
syncing vs. wireless syncing?
Answer: First, the number of devices:
The maximum number of devices on a wireless network is approximately, 255.
In a wireless environment, this number can be maxed-out by active users of
smart phones and other devices, not to mention large deployments of iPads.
Increasing it can be expensive and challenging. USB can cover 127 devices
for each host controller. If you want more, just add another host controller
(typically, another port on a MacBook or PC running Windows 7 or XP) for
another 127, and so forth.
Second, consider the future: Making an
investment in a USB sync-charge device is future-proofing. Apple devices
support WLAN sync but, if a school chooses to move to “some other” device
they may not have this luxury. Sticking with a USB port gives flexibility
and reduces the need to replace carts or the methods of syncing.
Third, SPEED: The speed of an 802.11b
wireless network is 54Mbps and an 802.11n network can support up to 300Mbps.
USB supports up to 480Mbps, which is considerably faster. And this is for
each USB controller. If WLAN signal strength is low or there is a high level
of “bad packets” or errors, the network will back off the speed, sometimes
to as low as 5Mbps. USB does not suffer from this backing off of speed.
Fourth, the cost of infrastructure, now and in the
future: The infrastructure required for a wireless network
covering a school or business can get costly and difficult to manage,
especially when there are a large number of users. As more users are added,
the speed of data transfer will go down, not only for the users trying
to
sync but also for those other users trying to surf the web or do file
transfers on laptops, etc.
The growing number of wireless devices are already testing the capacity of
many facilities’ wireless infrastructure. Adding iPad syncing can cause
significant user issues, especially when periodic syncing of files and apps
involves a large number of devices and large amounts of data.
Fifth, management and control: WLAN sync
is good in a home where, if something goes wrong, you can deal with it
easily. It is a different story in an institutional environment. With iPads
all over the place (not in a central location like a cart), WLAN syncing
could create issues of not knowing if they are all synced. If not, what has
to be done for any specific iPad to deal with the issue? Kids or teachers
could also turn off WLAN or change settings when using a network at home. A
USB cable doesn't have this issue.
During a wireless sync, an iPad may move out of WLAN coverage. What happens?
Does anyone know?
What types of cables work with the
DS-IP-SYNCCHARGE devices?
The DS-IP-SYNCCHARGE is provided with a power cable that plugs into the
wall and a certified USB cable that goes from the DS-IP-SYNCCHARGE to your
computer’s
USB 2.0 port. We recommend that you use the cables provided
by Apple with each iPad to connect each iPad to the DS-IP-SYNCCHARGE, you use the cables provided by Apple with each iPad. If those are not available, be sure to use either an Apple-provided cable (USB-to-30-pin connector) or a cable that is not only USB 2.0 certified but meets Apple’s specifications. Many inexpensive third party cables are either not durable enough for frequent charge and sync use or are not properly shielded or configured, which could effect the charge and sync function. Datamation Systems offers a bundle of certified USB cables of a type we have had tested to assure their compliance with these standards. We encourage you to purchase Apple-provided cables or contact us for more information.
How long does it take to charge 16 iPads using the DS-IP-SYNCCHARGE
or DS-IP-PP16 devices?
Note: These test were done before the release
of the latest iPad in March 2012, with it's
larger battery. Our devices still provide the
optimum charging for the newest
iPads but the
charge time may be longer because of the larger
battery (42 watt hours vs 25).
Charging speeds for iPads: We ran some tests, charging iPads that had been completely depleted, to see how long various methods took to re-charge them from 100% empty to 100% full.
We found the following:
USB port 2.0: On a desktop PC, it took 13 hours 30 minutes to charge a single iPad through the trickle charge on the USB port. The iPad does not display that the unit is charging. We have heard that this can take longer if it is done on a computer or notebook that goes into sleep mode.
On some multi-USB hubs (even powered hubs), the USB charge shares the available power supply and would take even longer. On one 24-port hub we reviewed, the
unit had a 22.5W power supply which gives less than 200mA per port so trickle charging would take more than twice as long as even the worst PC port. If the iPad is used daily for a few hours, the net charge in the iPad (if charged on this hub each evening) would go down.
Plugged into the Cambrionix C3 USB board used in the DS-IP-SYNCCHARGE: A complete empty-to-charged cycle took 4 hours, 35 minutes. According to Cambrionix, this charging time is the same as would be using the charging block supplied with the iPad itself. This would be the time required whether you are re-charging one or 16
iPads, as each port is provided with the full power required.
If the charge status of the iPads is not 100% empty, the time would be less.
How long does it take to sync 16 iPads to iTunes using the DS-IP-SYNCCHARGE devices?
Based on tests conducted by Cambrionix, using a current MacBook and a current version of iTunes, testing iPad and iPod devices with Apple-supplied USB-30 cables, it
took 70 seconds to sync a 1000MB file to three devices. Based on their calculation of the maximum capacity of the USB 2.0 port and the number of ports, they estimate
that it would take 5.3 minutes to sync simultaneously the same 1 Gig file to 16 devices. Other factor as may have an impact on sync speed (such as the host system, the type of file, number of files, etc.), but this is the best estimate based on the tests.
Can we use a Mac mini, G5
or Windows PC to sync to 16 iPads?
If the host computer has a USB 2.0 port and runs a current version of
iTunes, it will be able to communicate with the DS-IP-SyncCharge. For
Windows computers we recommend the use of Windows 7 or XP.
A MacBook has multiple USB ports. Can you plug in two DS-IP-SYNCCHARGE devices into each port and sync 32
iPads at one time?
Yes. The DS-IP-SyncCharge is addressed as a USB device by each port the same way iTunes would address a single iPad or iPod plugged
directly into a USB port. But, in the case of the DS-IP-SyncCharge,
the Macbook or other host will recognize all the devices plugged into the 16 ports of each device.
What are the minimum requirements of the Apple computer to be able to sync?
The Apple computer must have a USB 2.0 port and be running the current version of iTunes. If you have specific questions about your Apple equipment, you should
contact your Apple representative.
How can I find a basic how-to for syncing multiple iPads?
A school tech blog offers some advice with a how-to video:
http://cisdtech.com/2011/08/02/sync-several-ipads-using-Netsafe2-ip-sync-and-charge-cabinet/.
Can multiple Sync-Charge boards be linked to allow communication with many iPads (50, 100 or more)?
Multiple Sync-Charge hubs can be
plugged into USB ports on a single host computer. Using a Mac, the USB
device limit is 127 per host controller. The board used in the Datamation
Sync-Charge consumes 21 of the 127 devices and each has a hub depth of two.
The USB maximum hub depth is five. A USB hub device consumes one of the
allowed 127 devices regardless of whether there are any downstream devices
connected.
So, if you have one 'master' C3
(Sync-Charge board) you can connect an additional five C3s to it. This would
give you 11 ports spare from the master, plus 80 ports from the other 5 C3's
-- or 91 ports total. These 91 ports consume 126 of the 127 allowed to one
host controller. This would be the way to make best use of a single USB host
controller.
Most computers have more than one
host controller so you can do the same again (on the same host at the same
time). In "system profiler," you should be able to see
the number of
high-speed USB host controllers on your host computer.
Would
off-the-shelf USB hubs work to connect multiple C3 Sync-Charges?
Yes, absolutely. We have had customers use a number of C3 devices all
connected to a bus-powered USB hub. Just make sure it is a high-speed hub
(480Mbps). Knowing more about the application will help us help you more.
Can we daisy-chain C3 Sync-Charges to one
another, and, then, to a host computer?
Because there is a
limit on the allowed 'hub depth,' you can only daisy chain one C3 onto
another C3. It is better to use a 'star' methodology, as described above.
I have
a variety of USB devices that I would like to charge. Is there a
universal USB charger?
Even though the “U” in USB stands for
“universal,” not all USB devices have the
same power requirements for charging nor do
they all communicate their charge status
or
use the same pin configurations. For many
applications, this is the holy grail of
charging. The USB charging and
charge-and-sync hubs we provide will charge
a wide variety of devices, but they are not
universal.
If you offer certain, specific platforms
(models or makers of MP3 players, smart
phones or tablets), we may be able to test
them on our USB hubs. If there are models
we
cannot charge, we may be able to modify our
boards to accommodate them. For example, we
recently created a version of our 16-port C3
sync-charge board to
work with the Samsung
Galaxy and have also created boards to work
with the Dell Streak tablets.
We have hubs that provide two classes of
power to each USB port: (1) 500mA, which is
the standard power provided in most USB 2.0
ports; and (2) 2.1A, which will charge many
devices with lower power requirements but
all the way up to iPads, which need 2100mA
for their optimum charging.
All the Cambrionix boards and the enclosures
and power supplies we provide are created
for the professional user, not consumers.
They are durable and built for
constant use.
They can be used in engineering and
institutional environments where they are
not viewed as disposable consumer hubs.
Here are some notes on the form-factors that
charge, some of which also sync to a host.
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DS-IP-PP16
(PowerPad 16) (16 port charging
hub): Designed for Apple
products (all iPad models, iPods and iPhones),
this will charge up to 16 USB
devices and deliver a reliable 2.1A
to each USB port. It may work with
other USB devices. If you have an
Apple AC adapter of the type
provided with an iPad (or can borrow
one), plug your devices into a USB
cable and see if they charge when
the USB (A) end of the cable is
plugged into the little white Apple
AC adapter when that adapter is
plugged into a wall socket. If they
do, they will probably charge with
the PowerPad 16. No connection to a
host computer is needed.
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DS-IP-SC-49 (49 port sync hub):
This will sync up to 49 USB devices
to a host, but it also provides a
constant 500mA of power to each USB
port so it can charge some devices
that only require that power for
charging.
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DS-CH-32-500 (32 port charging hub):
This will provide 500mA of power to
each of 32 USB ports. It does not
require a connection to a host (like
some other USB hubs) but can charge
in a standalone configuration.
Again, it is not universal but it
will charge many types of
USB-chargeable devices (including
iPods and iPhones).
DS-IP-SyncCharge (16 port charge-and-sync
hub): This device can be used on a tabletop,
mounted in a cabinet or placed in a case for
portable charging and syncing.
It has two
modes: charging (at 2.1A per port) and
syncing (for communicating to a host to sync
content). It was designed for Apple devices
and works with iPods,
iPhones and all iPad
models
(which require the 2.1A power for quick
charging). As with the DS-IP-PP16 PowerPad
16 above, you can test whether this will
charge
devices by using trying them with a
USB-AC Apple adapter. Virtually any USB
device that will be addressed by a host
computer will communicate to the device for
purposes of syncing.
The DS-IP-SyncCharge may also be of interest
because it has some unique features that
allow you to communicate with each port
through a serial connection. You
or your
systems integrators can write simple
software scripts that can control each
device through its computer control mode. No
other professional hub has that
capability.
It could, for example, allow you to turn on
or off the charge or sync mode at a certain
time of day.
Are your USB charging and sync-charge devices Energy Star compliant?
All the Datamation
Systems USB charging and sync-charge devices
are provided with power supplies that meet
Level V or equivalent efficiency standards
and, therefore, meet Energy Star standards.
In some ways, their use can be more energy
efficient than using large numbers of
individual AC adapters for charging
Do your sync devices work with the new Apple Configurator?
We have tested the new Apple
Configurator tool with the new iPad and our C3
SyncCharge devices (DS-IP-SC-16).
It works very nicely. See below for the latest
tests we did, showing that more than 30 iDevices
can be controlled with Configurator, using a
combination of our hubs and carts.
Can we use Configurator with your sync devices (carts, cabinets, etc.) to work with more than 30 devices at a time?
We just tested the Apple Configurator
tool with three Datamation Systems
carts (DS-MINI-IPCS-32). We visited a school
that had three of these sync-charge carts, each
of which was holding 25
iPads. We connected all three carts to a small
Belkin USB hub so we had 75 iPads connected with
a USB cable to a host MacBook on which
Configurator was installed.
Configurator established a connection with all
75 iPads and moved from prepared mode to
supervised mode, suggesting that the 30 device
limit that has been discussed
is not a limitation of
Configurator, but just what may have been tested
using a syncing cart that is only limited to
supporting 30 devices. It appeared that all 75
iPads
would have been able to be
controlled simultaneously in supervised mode.
If we used this arrangement to do IOS updates,
we understand that Configurator would only
permit updates to ten iPads at a time, but it
would pick up new connected devices as old ones
are completed (in batches of ten) without
additional intervention.
Based on this, we assume that our 49-port
professional USB hub (DS-IP-SC-49) would permit
a user to update 49 iPads at a time using
Configurator and a MacBook.
More than one of these
49-port hubs could be connected as well.
While we have not tested the limits of these
configurations, we would guess that the limit
associated with a USB controller (127 devices)
may apply.
We welcome any experiences you may have had.
Please send them to us by email or with our
on-line contact form.
Do your USB chargers accurately measure the charge status of the device batteries being charged?
There have been some reports recently about devices (such as iPads) or their hosts (such as PCs or MacBooks) not showing accurate charge status. Measuring power
into, or consumed from, a battery is not a precise or accurate art.
The accuracy of charge status readings is a trade off between factors such as electronic circuit complexity, cost and battery life. For example, high accuracy means monitoring power in/out very fast and 100% of the time keeping a processor or some other intelligence-consuming power itself!
In order to determine power charge status, your device needs to know two of the following: voltage, current, resistance. Measuring these parameters is not 100%
accurate and not even the battery charger voltage can be assumed to be 5V (it's +/-5%). Also, the circuit components used to measure the values have tolerances
which vary over a certain between batches and so their precise values cannot be assumed.
An accuracy of 10-20% on the battery level sounds like an acceptable level. Making this more accurate is likely to create a detrimental effect on the system's battery life as the algorithm would sample the power levels more frequently to avoid missing large, fast power spikes, etc.
In summary, some level of inaccuracy is to be expected and the design of the systems involves trade offs. This is normal and applies, not just to our chargers, but to all devices that measure charge status.
Why do
amps matter when you consider a USB charging (or
charge-and-sync) device?
This is a link to a great layman's description
about how battery chargers behave and why amps
matter when choosing a charger or sync-charge
device. It was prepared
by Cambrionix, the leader in professional USB
charging and syncing solutions. Cambrionix USB
technology is used in Datamation Systems iPad
and tablet products.
Because they are in the UK, they refer to
"flashlights" as "torches."
Click here for more information.
