Serial Dilemma. What are your options without a Serial Cable?
The use of the most humble, and very much legacy RS232 has remained such a
stable of the Handheld PC community that most of us take it for granted the
fact that we are even using them.
For many of us, the serial cable, ambling along at no more than 115.2 Kbps is
a means to an end, simply being a step through the hard reset procedure to the
faster paced world of the 10/100 Mbps Ethernet connections.
The requirement on some sort of Serial connection before you can migrate to
faster Wired or Wireless network connections does pose an interesting problem.
With much of the community now being in the legacy arena, and inventories of
the proprietary cables dwindling - if not already depleted. What happens if
you find that your precious serial cable has been run through by a renegade
scissor blade, or indeed has been eaten by the proverbial dog?
Heralding the benefits of eBay, or even the hpcBay here on HPC:Factor as a solution
for some models of device is certainly a viable answer. HP and NEC devices for
the most part aren't currently lacking in the availability of second hand, or
indeed shrink-wrapped serial cables. Though for IBM, Hitachi, Philips and others
it is more down to the throw of a die as to whether you can find something suitable.
If it comes to it, the usability of the H/PC itself must inevitably come into
questions if you have nothing at your disposal to allow you to synchronise.
Synchronisation is part and parcel of the backup process, and with critical
PIM information, taking chances for extended periods on not having that backup
facility at your disposal may not be something you are willing to consider doing.
If you are in a situation in your PDA life where you face the prospect of having
to wait for an indeterminate amount of time for a cable to come up on eBay.
How long are you willing to wait?
How long can you keep going without synchronisation, without the ability to
install new software
and how long can you trust yourself not to let it
If the answer to any of those is not long, then it may be time to explore some
of the options available to you.
Additional Serial Cables
First, and most obviously, you could stockpile additional serial cables while
you still have the opportunity. This could be expensive, and while it would
give you piece of mind you are going to be - for the want of a better word -
hogging all the cables.
The most critical point that should be considered on continuing to use serial
cables is whether you have plans to upgrade your computer in the near future.
64-bit computer is upon us, and almost certainly if you want to purchase a new
computer, you are going to look at a 64-bit system. For PC manufacturers and
motherboard vendors, it is becoming less and less imperative for them to provide
legacy Serial and Parallel ports on their hardware. This is particularity prevalent
in the notebook industry where often neither is being provided. Within the next
12 months it is likely that this is going to become the norm, rather than the
exception within the industry.
If you find yourself in such a situation, there are of course USB solutions,
such as the Belkin F5U109ea USB PDA Adapter, and while effective. They may not
provide a long-term solution as drivers may fail to materialise for the latest
versions of Windows, as demand simply dwindles and Microsoft themselves do not
formally recognise such devices as part of the Windows driver catalogue.
This solution, for all, will inexorably return to the issue of serial cable
availability. So as an attempt to try and extend the life span of your investment
you may wish to explorer other options.
Universal Serial Bus
Universal Serial Bus, or USB is the standard developed essentially to replace
the RS232 Serial port and the IEEE-1284 Parallel port interfaces. USB in recent
years has become far more than just a medium for connecting such devices, and
through the progression of its universally recognised standard, looks set to
remain with us for a considerable amount of time.
the perspective of most Handheld PC users, the promise of a 12 Mbps USB connection
to sync over is more of a double-edged sword. The number of Handheld PC's with
USB support in itself is limited, and of those not all will have client USB
ports, specifically for the purpose of connecting to, and synchronising with
an ActiveSync PC.
Your device will either have this capability, or it will not. If it doesn't,
unfortunately you are out of luck, as this is something that cannot be added.
If it does, then by purchasing an inexpensive USB controller card (if needed)
for your PC, such as the D-Link DU-520, and an equally inexpensive USB cable
the device is automatically future proofed for as long as the USB specification
remains in effect.
For Jornada 700 series owners, this is certainly the most productive way
to improve synchronisation longevity - but you do require a cradle.
The IrDA specification is a way of broadcasting digital signals using electromagnetic
pulses between devices, without the need for cables.
Infrared communications is the first of two options, which are classed as being
Personal Area Networks (PAN). Unlike Local Area Networks (LAN) or Wide Area
Networks (WAN), PAN communications are not restricted by ActiveSync's security
systems - as such you can use them to create new device partnerships, as well
as synchronise and perform all the other tasks that you would when using a regular
Microsoft foresaw the need to include synchronisation and communication support
beyond that of the serial cable, and from the beginning included Infrared in
the hardware design specification for the Handheld PC. This makes Infrared a
solution which can be used against any generation of Handheld PC device, from
Windows CE 1.0, right through to the current generation of Windows CE 5.0 hardware.
When used with ActiveSync, Infrared communications are limited to a maximum
transfer rate of 115.2Kbps, the same as a regular serial port and carry a maximum
range of up to 5m (16ft). Despite this limitation in the software implementation
modern Infrared communication devices are designed to be able to operate at
far greater speeds.
With Infrared there are several different ways that support can be implemented
- Built in adapter on PC motherboard (especially common with notebooks)
- Extension dongle from COM port (Most [but not all] desktop motherboards
with dual COM ports allow this, providing space for an optional IR lamp to
be fitted to the second COM port socket; uncommon)
- USB IrDA lamp
USB Infrared devices such as the Belkin F5U235ea adapter may be used to add
Infrared capabilities both to desktop PC's and laptop PC's running Windows 98
or higher, integrated motherboard or COM port extender dongles may be used with
Windows 95 or higher.
USB Infrared provides a well-covered solution for any H/PC user, but Caveat
Emptor should be applied.
2000, Windows XP and Windows 2003 all make use of a radically different Infrared
protocol layer than Windows 95, 98 and Millennium. For Windows CE 2.0 and above
users, the answer is to upgrade to ActiveSync 3.5 or higher (3.8 recommended)
which fully supports the Windows XP driver layer.
For any Windows CE 1.0 user, the retired H/PC Explorer software was written
to make use of the Infrared layer under Windows 9x, and is simply unable to
communicate using the newer system.
Secondly, Windows NT 4.0 lacks any degree of formal Infrared driver support,
though some expensive third party drivers do exist.
Lastly, a note of caution about some of the cheaper, generic adapters that are
prevalent in the market place. Often the unbranded models lack adequately written,
unsigned (by Microsoft) drivers. With these adapters there are a large number
of reports from end users about devices being unable to communicate at all with
the host system. As a result of this, we recommend that you look for a branded
adapter, from a company that has a support department that you can contact for
assistance in the event that you do experience problems.
Like with USB, the Infrared specification will continue to be supported both
by ActiveSync and by Microsoft Windows in subsequent releases.
It provides the cheapest and most readily available option to all generations
of H/PC users, but should be researched before taking the plunge.
CESD-C-0017 for more information on
the Infrared Protocol
CESD-C-0020 Synchronising Windows CE
1.0x over an Infrared (IrDA) Connection with Windows 95 and 98
CESD-C-0021 Synchronising Windows CE
1.0x over an Infrared (IrDA) Connection with Windows NT5
Bluetooth in comparison to the other communication methods that I have outlined,
is a relatively new standard. Just as with Infrared, Bluetooth is considered
to be a Personal Area Network (PAN), which means it can be used to create ActiveSync
order to use Bluetooth you will need to be using a modern version of Windows
(ideally Windows XP SP2) on your host PC, as well as HPC2000 or higher. While
there are some experimental drivers available for a very limited number of Bluetooth
adapters, these are restricted beta versions, and at this time do not allow
Windows CE 2.x devices to synchronise through ActiveSync (a process known as
Bluetooth over Serial).
Like with Infrared, Bluetooth connections are limited in range to only a few
metres, but unlike Infrared they do not require a direct line of sight between
transceivers, increasing their functionality.
Adding Bluetooth support to your Handheld PC also opens up other potential uses,
with additional hardware devices such as headsets, connections to your cell
phone and Bluetooth networking being available.
ActiveSync over Bluetooth is a relatively new phenomena, with formal synchronisation
support only being recognised with the ActiveSync 4.0 release, though it is
possible to synchronise with ActiveSync 3.7.0 and higher.
Products such as the Socket Communications Bluetooth CF Connection Kit are
available in the CF form factor, which can be used with a PCMCIA adapter if
required, but be warned. These solutions carry hefty price tags, of upwards
of £80 ($140, €114, ¥16,000 est.) and can potentially provide
a security weakness when considering rollout for corporate mobility solutions.
An option you may not have considered
Hardware solutions are a good way to safeguard, and to future proof your investment,
but if you already have a synchronisation partnership established, and want
to go down the networking path there is another alternative. An alternative
that will, at least in the short term offer you the ability to continue synchronising
fundamental question on this is: What is a partnership?
The answer to this is simply that a partnership is nothing more than a shared,
randomised hash that is present on both the Host PC and the Handheld PC. Stored
along side this is the specific detail that makes up the personal characteristics
of your device, and respectively a little information about your host.
This information is stored as applicable between the registry on your PC, and
the registry on your Handheld PC.
By knowing where in the registry to look, and which pieces of information to
collate, you can create a registry file which you can reintroduce on both the
Handheld PC and on the Host PC, even after a hard reset / format. With this
in place, ActiveSync on either side will be oblivious to the fact that in reality,
it has never initialised the partnership wizard against its opposite number.
This solution will not assist you if you have a new device and no existing
partnership, however by backing up the registry files in the correct place,
you will be able to synchronise over a LAN/WAN, and still be able to fully hard
reset your device without relying on a potentially messy backup - so long as
no changes are made to the partnership formatting of the ActiveSync host client.
For more information see CESD-C-0027
Creating a manual partnership backup for ActiveSync 3.8 connections.
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