In its two-pronged quest for an enterprise tablet design that takes advantage of the popularity and familiarity of consumer tablets but in a more durable package, Zebra succeeded. In fact, they succeeded almost too well. The all-black tablet is almost anonymous. No glitz, no color, no chrome strips or fancy textures. And no need for an eye-catching protective cover that almost all consumer tablets reside in.

The ET56 simply blends in. It's innocuously pleasing and a very clean design, but it certainly doesn't catch the eye. Except for the little Zebra logo in the back, you wouldn't even know who makes it. So we're not talking status symbol here.

And that's perfectly okay for an enterprise tablet. It's supposed to be a tool for the job. And that it is. A very practical one, in fact. The black plastic housing is slightly textured, which makes it not quite as slippery as most consumer tablets. Though they are unmarked, everyone knows that the small button on a tablet is on/off and the longer one is volume up/down.

There's no need to mark ports either. The docking connectors are obvious. As is the sole port that sits behind a protective rubber flap. The port is one of the new USB Type-C kinds that's reversible and can be used for all sorts of connectivity. You may have to get a USB Type-C to Type-A adapter (very cheaply and quickly available via Amazon Prime). The two cameras don't need a notch. The battery is externally accessible and replaceable.

There's a large bezel area around the actual LCD screen. You can actually hold this tablet without the screen going nuts, as is the case with all those new bezel-less smartphones and tablets. And the plastic housing is very lightly raised above the glass bezel, providing protection. It all makes so much sense and ET56 users will quickly come to appreciate all this quiet goodness.

But in case you wonder how Zebra managed to put the customary industrial-grade scanner into such an impressively slender design, even Zebra couldn't do that. Instead, the ET56 uses an expansion back system to extend functionality. Three such backs are currently available. They add a very clever rotating handstrap, or Zebra's own SE4710 or SE4750 enterprise scan engines together with the rotating handstrap. And an optional hot swappable battery can be added to any of those expansion backs. Below you can see what the scanner expansion back looks like.

The expansion backs screw on. That means the internal battery is no longer as easily replaceable as it is without the backs. On the plus side, the optional second battery that goes into each of the backs doubles battery life (but, of course, also adds weight).

The battery compartment is sealed by a flexible plastic cover that snaps on. It is unlikely that it'll ever work itself loose accidentally. Do keep an eye on the rubber pressure seal that's molded onto the inside of the compartment cover.

The slender (3/16th-inch) battery itself is a rechargeable Lithium-Ion Polymer design rated at 7.6 Volt, 3.3 Ahr, for a total of 25.1 watt-hours. As shown above, the battery needs to be removed in order to get at the tablet's nano-SIM slot and micro-SD card slot.

Zebra ET56 Benchmarks and Comparisons

PERFORMANCE COMPARISON	Zebra	Zebra	BAK	Getac	Juniper	Trimble
Model	ET56	L10	Seal	T800	Mesa 2	Yuma 7
Device type	Semi-rugged tablet	Rugged tablet	Rugged tablet	Rugged tablet	Rugged tablet	Rugged tablet
Screen size	8.4"	10.1"	8.0"	8.1"	7.0"	7.0"
Year tested	2019	2018	2018	2017	2016	2019
Processor Type: Intel	Atom	Pentium	Atom	Atom	Atom	Pentium
Processor Model	E3940	N4200	x7-8700	x7-8700	Z3735	N4200
Processor Code	Apollo Lake	Apollo Lake	Cherry Trail	Cherry Trail	Bay Trail	Apollo Lake
CPU Speed	1.60 GHz	1.10 GHz	1.60 GHz	1.60 GHz	1.33 GHz	1.10 GHz
CPU Turbo/Burst Speed	1.80 GHz	2.50 GHz	2.40 GHz	2.40 GHz	1.83 GHz	2.50 GHz
Thermal Design Power (TDP)	9.5 watts	6.0 watts	2.0 watts	2.0 watts	2.2 watts	6.0 watts
CPU Mark	3,986.7	5,235.3	2,406.3	1,620.3	1,863.5	5,275.0
2D Graphics Mark	159.1	139.4	104.8	104.7	117.9	138.1
Memory Mark	440.3	672.8	563.8	284.1	358.7	632.6
Disk Mark	1,188.4	4,407.8	547.4	601.1	917.2	770.9
3D Graphics Mark	267.3	179.8	249.7	162.6	148.3	237.5
Overall PassMark	1,447.7	2,457.3	905.3	643.0	785.5	1,740.1
ALU	30,953	41,063	29,906	21,118	24,977	39,220
FPU	27,937	40,731	22,581	18,082	19,656	31,020
MEM	33,470	29,692	25,230	17,648	25,013	33,497
HDD	26,250	39,300	22,211	18,620	25,344	25,470
GDI	2,818	13,452	4,436	3,430	4,130	6,412
D2D	4,000	5,710	3,200	2,845	2,800	2,700
OGL	3,845	11,210	4,011	2,984	2,804	4,620
Overall CrystalMark	168,219	181,158	111,575	84,727	104,724	142,939

When looking at the overall results, the first thing you'll notice is that in benchmark testing the ET56 is doing very well against some highly regarded rugged tablet competition. In fact, the numbers generated by the ET56 are better than even high-end rugged notebooks were capable of just a few years ago.

That said, note the significant differences between the devices, even though all are powered by processors using Intel's Atom architecture.

Also note that some devices, such as Zebra's own fully rugged xSlate L10, are actually high-end devices that are also available with lower-end, more economical processors. Equipped with one of its high-end Core processor options, the xSlate L10 reaches an overall PassMark score of almost 6,000.

Finally, note that the type of mass storage can have a significant impact on overall device performance. In small handheld rugged tablets eMMC technology is predominately used, whereas larger higher end devices will use much faster SATA/600 or even PCIe NVMe solid state mass storage.

In our day-to-day testing, the Zebra ET56 felt quick and responsive, and was up to any workload we threw at it.

Battery life

Battery size, weight and life are always major issues in every mobile computing device. And especially so in a device that needs to be as thin and light as possible. Battery technology has improved substantially, but not as quickly as processor and storage technology. As a result, it's still often a trade-off between size, weight, cost and battery life. How did Zebra handle the battery issue in the ET56?

First of all, the battery is exchangeable, externally accessible, and hot-swappable. And those using an ET56 with the scanner attachment can go for a second optional hot-swappable battery via the innovative expansion back to more than double the battery run time. That, of course, comes at the cost of extra weight, which can be an issue for scanner-intensive operation.

As is, the ET56 main battery packs 25 watt-hours. That compares, for example, to 33 watt-hours in Apple's latest 9.7-inch iPad. People generally expect at least 10 hour battery life from an iPad. How does the ET56 compare against that?

Zebra ET56 Power Draws (at idle)
Backlight level	0%	50%	100%
Max Battery	1.6 watts (15.7 hrs)	2.9 watts (8.7 hrs)	4.2 watts (6.0 hrs)
Max Performance	1.8 watts (13.9 hrs)	3.4 watts (7.4 hrs)	5.3 watts (4.7 hrs)

We used PassMark's BatteryMon to find out. With the Windows 10 slider moved all the way to "Best battery life" mode, and the screen brightness slider set to 0% we saw a stunningly low minimum of 1.6 watts. With the backlight set to 50%" it was 2.9 watts, and with the backlight at 100% about 4.2 watts. Dividing the available 25.1 watt-hours of a fully charged battery by the lowest observed battery draw of 1.6 watts would indicate a theoretical battery life of 15.7 hours.

Putting the Windows 10 slider to "Best performance" and setting the backlight to 0%, power draw was 1.8 watts, just a tad higher than in battery conservation mode. With the backlight set to the 50% level, it was 3.4 watts, and with the backlight at 100% 5.3 watts. This means that in "Best performance" mode and backlight as bright as Windows sets it, battery life drops under four hours.

Bottomline: the Zebra ET56 can last an amazing 16 hours. But using the tablet in "best performance" mode and with screen brightness cranked all the way up — and the ET56 has a very bright screen — the smallish battery drains much more quickly. Which is why the ET56 has a bridge battery that allows hot-swapping to a fully charged replacement battery.

The usual caveat: benchmark power drawdown simply measures power draw of the device idling along. In real life use in the field, the tablet may go from periods of maximum load to going to sleep. Actual battery life can therefore vary dramatically.

Expansion backs

In order to create the slimmest rugged tablet possible while still offering a variety of options, Zebra designed a "expansion back" system with a silicon seal that bolts onto the back of the unit, replacing the battery compartment cover. The expansion pack communicates to the tablet via a set of pogo pins that press against contacts. Currently available expansion packs provide either just a rotating hand strap, or the hand strap and the SE4710 or SE4750 scanner module. Each of the expansion packs also has a battery compartment drawer for an optional second battery.

As far as the scanner options go, both are 1D/2D bar code scanners that use Zebra's PRZM technology that offloads part of the decode processing to the scan engine itself (for higher speed) and the MIPI (Mobile Industry Processor Interface) interface. The higher-end SE4750 can scan from longer distances, offer the choice of LED or laser aimers, and the SE4750 can not just scan codes, but also entire documents.

Excellent, spacious display

With a diagonal screen size of 8.4 inches, the Zebra ET56 offers significantly more display real estate than even the biggest smartphone (for example, 2.5 times as much as an iPhone 8 Plus), while still having an overall footprint considerably smaller than that of a 9.7-inch iPad.

The ET56 also offers exceptionally high resolution, up to 2560 x 1600 pixel. That's almost twice as many pixels as the ET50's 1920 x 1200 display. And the ET56's 359 PPI (pixels per inch) make it sharper than any iPad.

Finally, there's display brightness. Brightness — really luminance — is generally measured in nits. While the original ET50's 440 nits made it only marginally bright enough for outdoor use, the new ET56's luminance has been boosted to 720 nits. That's brighter than any currently available iPad.

To demonstrate how it works in practice, we did a series of outdoor comparison pictures with an iPad Air 2 that we use around the RuggedPCReview office. We measured the iPad's screen to generate 415 nits.

The three pictures below show the two tablets outdoors on a sunny East Tennessee morning in late July. Both display backlights were cranked up to maximum brightness, and both remain very readable. The ET56 display, though, is noticeably brighter when viewed from straight ahead as well as when viewed from angles. Both tablets use glossy screens with optical coatings, which is the current state-of-the-art for outdoor viewability.

The next three pictures show howw the ET56's glossy display handles reflections. Every smartphone and tablet user is familiar with the syndrome. As is, the ET56's extra brightness keeps it readable better than most.

We consider perfect screen viewing angles to be very important, and especially so in tablets that will be used in retail and other customer interaction deployments. The ET56 screen excels in that area. There are no contrast, color or brightness shifts when viewing the tablet from different angles, even extreme angles.

As far as the touch screen goes, it's, of course, capacitive multi-touch that can handle ten separate inputs. Unlike the larger ET51, the ET56 does not have an active digitizer option for those who like to use a pen. However, the ET56 has a Touch Manager utility that allows optimizing the touch screen for use in rain, for use with both fingers and a passive stylus, and also for use when wearing gloves.

Dual cameras

The Zebra ET56 has front and rear cameras, as is standard on most modern tablets. On the front is a 2-megapixel webcam. The rear camera is for picture taking and documentation. It has an 8-megapixel imager, and the pictures we took came out in 16:9 aspect ratio 3200 × 1800 pixel resolution, which makes for 5.76 megapixel. 4:3 aspect ratio is selectable as well, and that that results in full 8 megapixel pictures. We used the cameras in our review unit via the standard Windows 10 Camera application. Both cameras can be used for stills as well as for video.

Based on past experience with most cameras integrated into rugge mobile computing gear, our expectations were modest, especially when using the very basic Windows Camera app. For once, we were positively surprised.

While the Camera app settings are limited and, for example, won't allow image settings other than just the aspect ratio, users can actually opt for manual input in white balance, ISO, shutter speed, flash and exposure compensation. There's even manual focus, something we don't see often in Windows cameras.

What that means is that the ET56 cameras can be used for documentation on the job. That should be a given (why else include cameras?), but most such cameras don't even come close to replacing a dedicated camera or a smartphone. So major kudos to Zebra for doing better. These cameras can be used on the job.

The pictures below were shot with the ET56 rear camera in its 3:2 aspect ratio mode. The sample pictures are a mix of tasks that a field service professional may encounter on the job, and some of the flora around our offices. Click on the image to bring up a full-size version.

Video, too, is better than what we've seen from many cameras integrated into rugged devices. The camera generally doesn't fall behind and the maximum 1920 x 1080 recording format remains useful, even at just 30 frames per second.

Probably more than just "semi-rugged"

Ruggedness isn't easy to define. And that's especially so when the goal is to make something not as absolutely tough as can be, but simply tough enough for the job. Terminology doesn't help.

So Zebra went to some lengths positioning the ET56. And that's nowhere more obvious than in the ET56 introduction YouTube video. The ET56 is much tougher than those cheap, chintzy consumer tablets. But not as ugly and heavy as those fully rugged tablets. So there.

There are, of course, ruggedness tests. To guard against the ever-present danger of getting dropped, mobile computing gear is usually tested in accordance with procedures described in the governmental MIL-STD-810G, Method 516.6, Procedure IV. For a tablet one should expect immunity against four-foot drops, because that's about the height they'll fall if dropped while used in a standing position. Oddly, the ET56 is listed as being able to handle just 3.3 feet — a meter — albeit on concrete (most vendors test with plywood over concrete). Based on our experience, we think the ET56 can easily handle at least four feet on concrete, probably five. Zebra does offer a fix in the form of a "rugged frame," a protective case (see pictures left and right). That way, it can handle six feet. Honestly Zebra, re-test and go for four feet, it just reads better.

Devices like the ET56 may also be subjected to vibration, especially if used in vehicles. Testing for that is commonly done in accordance with the MIL-STD-810G, Method 514.6, Procedure I, Category 24, Fig 514.6E-1, which vibrates a unit while it is powered on at prescribed frequencies for an hour per axis. This test does not simulate an application environment, but rather suggests that a device that can pass that test will survive in the field. That's perhaps a bit vague and difficult to comprehend, but that's the supplied data.

On the sealing front, the ET56 is at the same IP65-level of ingress protection. The "6" means complete protection against dust, and the "5" means protection against low pressure water jets from all directions. What that means, is that the tablet can handle any degree of rain, but it shouldn't be hosed down with a pressure washer or submerged into water.

The operating temperature range is given as -4 to 122 degrees Fahrenheit (-20 to 50 centigrade). That's wider than the predecessor ET50, and it is good enough for virtually all conceivable operating environments, including commercial freezers.

Apart from the listed specs, our examination of the ET51 revealed exceptionally sturdy, common sense design and construction. The strong and rigid case with its magnesium frame inside keeps the unit from flexing. And unlike far too many rugged devices that use materials that scratch and dent easily, the ET56's industrial plastic body looks it can handle a lot of abuse.

Summary: The Zebra ET56 Enterprise Tablet

Business customers often find themselves in a difficult situation. Consumer tablets are inexpensive, staff knows and likes them, and so the temptation to buy a bunch of them and stick them in a case for a bit of protection is great. But it's rarely the best way to go. It's really better to get something that's built for the job, and Zebra's ET51/ET56 Enterprise Tablet is just that.

The ET51/ET56 comes both in 8.4 inch and 10.1 inch versions, with ET51 units being Wi-Fi only whereas ET56 units have both Wi-Fi and mobile broadband. We tested the 8.4-inch ET56 version. Even though it weighs only 1.2 pounds and is thinner than most consumer tablets in a case, it's hard to describe just how much more solid and trust-inspiring the Zebra ET56 feels. It's easy to hold, it's not going to get scratched or dented, it's clear that it can survive falls, its battery can be replaced in seconds if need be, it has a USB-C port instead one of those flimsy micro-USB jacks, and that's just the beginning.

While ruggedized gear often suffers from the dreaded "government issue" lagging in the technology department, there's no such thing with the ET56. Its really excellent 8.4 inch screen is both brighter and sharper than that of any iPad. It comes with Class 1 long-range Bluetooth. It's micro SD card slot can handle up to 2 terabyte. And its cameras are excellent (which is far from a given).

Additional functionality can be added via expansion backs that easily bolt on. Each of the available backs (currently offering two of Zebra's industrial-grade scan engines) has a very ergonomic rotating hand strap and also a drawer for a second battery that doubles battery life. The ET56 is powered by a very frugal Intel Atom quad-core processor that doesn't need a fan. We're not talking Intel Core performance, but the ET56 is quick enough.

Overall, the Zebra ET56 impresses. It is a convincing and remarkably well conceived and executed tablet design that enterprises can rely on. Much more so than on consumer tablets in a case. – -- Conrad H. Blickenstorfer, July 2019

Zebra ET56 Specifications (8.4-inch version, WiFi + WAN) Status Full review 07/2019 Product type Enterprise tablet Processor Intel Atom x5-E3940, 1.6GHz/1.80GHz CPU Thermal Design Power 9.5 watts OS Windows 10 IoT Enterprise Graphics Controller/Chipset Intel HD Graphics 500 (400 MHz base frequency, 600 MHz burst frequency Memory 4GB LPDDR4 RAM Display type TFT LCD with AG/AR film, optional sunlight-readable 1,000 nits display Display size and resolution 8.4" 2560 x 1600 pixel (359 ppi), 720 nits (measured 630 nits) Digitizer/Pens 10-point capacitive multi-touch, rain/glove-capable, optional passive stylus Keyboard Onscreen keyboard, optional USB or Bluetooth keyboard Storage 64GB eMMC Flash (user accessible micro SDXC card slot supports up to 2TB) Slots 1 x micro-SDXC, 1 x nano SIM Housing Polycarbonate over magnesium chassis Temperature -4° to 122°F (-20° to 50°F) Humidity 5-95% non-condensing Vibration Random: 0.022/Hz, 20Hz to 2khz 4g RMS 1 hour per axis Enclosure Class IP65 EMI unknown Shock: Transit Drop 3.3 feet to concrete per MIL-STD-810G; 6 feet to concrete per MIL-STD-810G with optional rugged frame Intrinsic safety unknown Certifications Inquire Size (inches) 9.0 x 5.9 x 0.5 inches (228 x 150 x 12.7 mm) Weight 1.2 lbs. (540 grams) as tested Power 7.6V, 3,300mAH, 25.1 watt-hour Li-Ion Polymer; optional hot swappable 7.2V, 3,400mAh (24.4 watt-hour) secondary battery Camera 2.0mp front-facing, 8mp rear-facing auto-focus with flash and geo-tagging GPS GNSS supports GPS, Galileo and Glonass with LTO technology for Assisted-GPS without sacrificing autonomous operation Scanning Available through the expansion back accessory: SE4750 or SE4710 integrated advanced imagers with hardware decoding NFC P2P: ISO 18092; Reader/Writer: ISO 14443 -A-B, MIFARE, FeliCa, ISO 15693, NFC Forum Tag Types 1 to 4; Card emulation: ISO 14443 -A-B-B, MIFARE, FeliCa RF Wireless dual band 802.11 a/b/g/n/ac/r/k/v WiFi with Bluetooth 4.2, 4G LTE, dedicated GPS, 1D/2D scanner Sensors Ambient light, gyroscope, 3-axis motion, electronic compass Interface 1 x USB Type-C, docking Price Inquire Website Zebra ET5X web Brochure Zebra ET5X brochure Warranty 1 year (also see see here)