June/July 2003

Our impression

Let's face it ­ there's never going to be a one-size-fits-all for mobile computers. The operations and applications are so varied that no single handheld computer is ever likely to fit the bill, however much functionality it might have.

But with mobile computers proliferating in warehouse and field operations, the headache of managing diverse, often incompatible, units is growing. So a mobile computer that has the potential to cut down that complexity should appeal.

That's what Psion Teklogix hopes its new 7535 unit will do. It is the first computer developed by the company that has enough flexibility to be used in both warehousing and field data-capture operations. Equipped with a radio and integrated scanner, for example, the 7535 is an automatic data capture unit. Add a GPRS card, and the same always-on connectivity is available in the field.

 

This out-on-the-road capability, together with its LCD screen and Windows CE.Net operating environment, can lure you into thinking the 7535 is a new-generation Psion Workabout, but it actually belongs in Teklogix's 7035 and 7030 wireless data capture family of always-connected handheld computers. (The Workabout replacement, the Roadrunner, is in development, and is scheduled to be available early in 2004.)

On the 7535, Windows CE.Net replaces the TekTerm terminal emulation operating system on the 7035. With CE.Net, the 7535 can run graphical-user-interface thick-client applications, yet it remains backwards compatible with text-only applications such as the 7035's Tekterm. Initially, the 7535 has CE.Net 4.1, but will migrate to the 4.2 version as soon as it is released by Microsoft.

The 7535 also incorporates other key mobile standards including Intel XScale architecture, Compact Flash and SD I/O expansion card slots for memory or peripherals such as radios, and 802.11b, Bluetooth and GSM/GPRS radio technologies.

The initial version works on the IEEE's well-established 80211.b wireless protocol, but Psion Teklogix says versions working on the 802.11a and 802.11g variants will be available within six months.

The scanning options include one-dimensional and two-dimensional radio scanning and RFID ­ plus a fuzzy logic capability, which enables the scanner to read barcode labels that have suffered up to 30 per cent degradation, Psion Teklogix says.

The 7535 is slightly cheaper to buy than the 7035, but the cost savings don't seem to have been made at the expense of the renowned Teklogix ruggedness ­ which if anything has been enhanced. This version can withstand 26 drops from 6ft (2 metres).

The 7535 uses the same single-piece moulded plastic construction first seen in the Workabout, so there is an element of family convergence here. It has a slot-in battery pack and is rated to IP65 for water and dust resistance (the 7035 by contrast is rated at IP54).

Psion Teklogix says the internal component most likely to need repair or replacement is the scanner engine. So removing four top-mounted brass screws (five times as strong as self-tapping screws) allows the scanner engine to slide out from underneath, better preserving the dust and weather resistance of the top section of the computer.

The optional Sharp hardened-glass VGA TFT colour screen is the same as that used in HP's Ipaq PDAs. Teklogix engineers apparently found that a polycarbonate screen was actually too strong; it could be pushed into the casing, where it is liable to damage the most expensive component, the logic board. A solid-state light emitting diode backlight for screen and keyboard has been chosen to eliminate fragile tubes.

The radio antenna fits snugly under the end cap for better protection. The laser lens is now in a pocket under the screen, where it is better protected from absent-minded prodding, and is said to cope with 50lb force before it breaks. The tethered port has moved from the bottom of the unit to the side.

The keys themselves have been hard-coated so letters and numbers cannot be scratched off and will withstand a million strokes before they wear off.

In an unscientific test of my own, I threw the unit 10ft on to a hard floor. This cringe-inducing treatment caused the battery to pop out, but it was easily reinserted, and there was no loss of data or other damage. The display simply returned to its condition before the power loss.

Rugged handheld computers have a reassuringly solid look and appearance, but the downside can often be heaviness that makes them tiring to use on a long shift. Psion Teklogix is particularly proud of the ergonomic design that has gone into the 7535 and it does seem to have paid off, especially in the pistol-grip model. The 7535 is only 100kg (4oz) lighter than the earlier 7035, but holding a 7035 in one hand and a 7535 in the other, I felt the weight difference seemed more. The explanation is that the 7535 terminal is so well balanced that you don't have to exert any pressure to prevent it tipping forwards or backwards.

The 7535 is one of the first industrial handhelds to deploy five-wire rather than four-wire touchscreen technology. Five-wire gives better control and resolution, and means if one wire gets damaged the screen will still function. In practice, it makes moving around the screen a lot easier and means the unit responds faster to the touch of your finger or stylus, so there is less pausing while you wonder if you have exerted enough pressure to input data or activate an application.

Our verdict

All in all, the 7535 seems a real winner that draws the very latest technologies into the Psion Teklogix range, whilst maintaining the faith with its Teklogix ancestry.