- 11. My PC already
has a built-in wireless card. Will that work with the
1. In addition
to assigning your own TCP/IP address, the PRAM WSL-2E
supports ESSID (network name), thereby ensuring you'll
connect only with the WSL-2E even if there are other
wireless local area networks.
of course is dependent on a number of factors including
PC card RF power, antenna gain and placement, line of sight
obstructions and spectrum crowding. With clean line of
sight between all antennas, a 50mW PC card, standard WSL-2E
antennas and relatively clear spectrum, you should have
a realistic range of 500 - 600 feet. Greater distances
(several thousand feet) can be achieved with high gain
antennas, the high performance PC card and proper antenna
pieces of software will be installed on the computer: WiNet® Manager,
which is the configuration utility that sets the TCP/IP
address, ESSID (network name) and other WSL-2E communications
parameters. The second program, installed only for Windows® 95/98/ME,
is the Serial Server Manager or SSM. The SSM runs in the
background controlling com port selection, redirection
and baud rate. Windows® 2000/XP/NT does not use SSM
and instead uses its own Device Manager controlling a Multiport
Serial Adapter driver. Both programs are easily installed
by simply running the installer from the software CD included
with the WSL-2E.
far as the PC card and WSL-2E are concerned, very little.
When the connection is re-established, you can simply pickup
where you left off. The deciding factor is how the manufacturer's
control software handles a lost connection. It may require
a restart, re-initialization, or it may allow you to simply
continue when the connection is re-established.
As the PRAM WSL-2E is IEEE 802.11b and WiFi compliant,
it supports full bi-directional communications.
are several advantages to the WSL-2E over a dual computer
a) Size and packaging If the second computer connected to the
equipment is a rack mount design, its probably two or three
rack spaces, heavy and fairly deep. If its a single rack
space, its probably very deep and requires rear support.
Even if you dont regularly set up the keyboard, mouse and
monitor, youll still need to carry them (another road case?)
as back up should your portable be unavailable.
If the second computer is a portable, its either going
to be set up and taken down with each use, or stored in a rack
drawer that is probably two to three rack spaces. Theres
now concern for cable slack at the rear of the computer to facilitate
drawer travel. Antenna options for PC cards are quite limited
as well. In either case, an external adapter (a dongle)
is needed to convert RS-232 and connect RS-485 devices.
The WSL-2E is one rack space, 8 deep and weighs only five
pounds. No adapters are necessary as the WSL-2E interfaces directly
with RS-232 and RS-485 devices using common connectors (male
DB9 and 3 pin XLR respectfully). The front panel has only four
status LEDs, and antenna options are numerous.
b) Reliability Dual computers means two hard drives, two operating
systems, two systems to configure and of course, twice the opportunity
for crashes and lengthy reboots. Operating two computers also
requires a second program (such as PC Anywhere® or Timbuktu®)
running concurrently for remote computer control adding yet another
layer to the question of stability. Additionally, even though
computers may be available in rack mount configurations, it doesnt
necessarily mean theyll hold up to the rigors of travel,
repetitive racking and un-racking or wide temperature and humidity
The WSL-2E contains no moving or delicate parts. Highly stable
firmware controlled microprocessors, a robust chassis, connectors
and internal construction along with its light weight, give the
WSL-2E a reliability unmatched by any computer. Further, once
the WSL-2E is setup with the WiNet ® configuration utility,
the only software application running is the chosen equipment
manufacturers control program.
The WSL-2E also supports hard wire connection to a computer for
configuration should a wireless connection not be possible. And
the WSL-2E boots in less than five seconds.
c) Operation The WSL-2E is fast: Theres no secondary control
program running; just a direct wireless connection between your
laptop or tablet computer and the WSL-2, with an extremely fast
serial interface. The WSL-2E is simple: Plug in power, connect
the data cable and antennas, select the data interface and turn
d) Cost Adding the cost of the second computer, WiLAN card, RS-485
adapter, PC Anywhere® or Timbuktu® , rack shelf/drawer
or additional equipment case and the added labor cost for assembly,
the total will certainly exceed that of a WSL-2; with less reliability,
taking up more space, adding complexity and be more time consuming
at the venue. Since the WSL-2E uses the 802.11b wireless standard
(and is WiFi compliant), you can use your current WiLAN PC card,
or any number of brands/models currently on the market.
PRAM has chosen the 802.11b standard for the RF data link,
the WSL-2E is more than just wireless Ethernet. It also
contains dual serial interfaces (RS-232 and RS-485) in
a package far more appropriate to the needs of production
professionals. The WSL-2E is a comprehensive, single piece
rack-mount solution for pro audio/video/lighting control.
When the prices of its component capabilities are calculated,
it is actually a far more cost effective solution for multi-format,
reliable wireless control.
the serial modem to be carried with the laptop or tablet
computer will require a high capacity battery for power,
a power cable, battery charger and some type of carrying
case(s) for both the modem and the battery. There will
also be the DB9 cable connected between the computer and
the modem. The small, parasitically powered serial modems
that connect directly to the RS-232 port on the computer
typically have a maximum baud rate of only 19.2Kbps, are
very low power and have a permanently attached, easily
damaged antenna. Compare all this to a single PC card inserted
into your laptop or tablet computer.
Second, an adapter will still be needed to convert RS-232 and
connect RS-485 devices.
Third, two serial modems and the necessary peripherals will essentially
equal the cost of a WSL-2, while being a very cumbersome package.
Fourth, serial modems can have enough latency to confound a number
of pro audio/video/lighting manufacturers control software.
Lastly, there may often be a mixture of both serial and Ethernet
protocols in a venue or on a tour. The WSL-2E is a simple, one-box
solution that addresses all of these formats.
this class of device, the FCC mandates the use of a unique antenna
connector, unless the antenna is permanently affixed to
the equipment. The reverse gender TNC connector used is
becoming a de-facto standard for the 2.4GHz ISM band. We
have found it to be both sturdy and reliable, as well as
providing the least amount of RF signal attenuation, thus
improving performance and maintaining range specifications.
PRAM has a complete inventory of antennas and low loss
coax with this connector, as well as antennas for the PC
cards to fulfill any standard or higher performance requirement.
WSL-2E system uses the 802.11b IEEE standard which, among
other things, specifies frequencies in the 2.4GHz (2400MHz)
range, putting it in the microwave band. Given these very
short wavelengths (a bit less than five inches), virtually
everything, including non-metallic objects become obstructions.
Thus, unobstructed Line of Sight between antennas
becomes critical. Although you will in fact achieve a certain
amount of penetration, your goal should always be a clear
RF path. If obstructions are unavoidable, use of high gain
directional antennas, short coax runs and/or an RF amplifier/pre-amps
will help in achieving a stable, consistent RF connection.
however these computers typically use a 35 to 45 milliwatt
card with an internal antenna. The combination of the low
RF power and the computer body blocking usually all but
one plane of the antenna results in significantly less
than desirable range and connection stability.