The bench test 2: Potential star

The operating menus of most security and surveillance devices are password protected, and we have become quite adept at playing hunt the PIN on Bench Test product samples.

Normally the devices we see are factory fresh and still on the default PIN or password, which is generally mentioned somewhere in the user or installer manuals. Occasionally it's on a sticker somewhere on the case and a few times they've turned up on labels inside the shipping container, but ninety-nine times out of a hundred (and yes we have been doing it that long...) it is found and the Bench Test proceeds apace.

We're only telling you this because of the fun and games we had with the Dallmeier DMS 240, an otherwise respectable and quite well behaved digital video recorder. The password was nowhere to be seen and the review ground to a halt. To make matters worse after it booted up it emitted a fearful whine, which we suspected was some sort of alarm, which could be switched off if only we could get into the menus – but we'll come back to that in a moment...

After almost two hours of fruitless searching and trying every possible combination of every default login we've ever encountered – and we've seen quite a few – we finally conceded defeat and called the service department, still convinced we'd missed it in one of the three manuals (one paper, two on disc).

"It's definitely there," we were told. "Okay, but on what page?". After much shuffling of paper and tapping of keyboards belief in our sanity was restored and tech support admitted it wasn't in any of the manuals sent to us. Our friendly helper was also able to sort out the terrible whine. It was an error signal, caused by the system looking for an optional add-on storage unit module, which we had been sent for testing but hadn't got around to connecting.

There's a moral in there somewhere, and from now on if the password isn't in an obvious place or takes more than five minutes to find we'll be on the phone. Instruction manual writers and editors please take note!

We have been assured that new manuals, now being translated, will contain the elusive logon information, so gripe over and we'll proceed with the core features.

The DMS-240 is a hard-disk based DVR with 8, 16 or 24 camera inputs with audio recording on all channels (our test sample was the 24-channel model). A single 250Gb drive is included as standard. There is built-in support for up to 1 terabyte of on-board storage using approved SATA drives, which are mounted on two lockable slide-in trays for quick and simple upgrade or exchange. The optional external storage module mentioned a moment ago is basically a box with lockable trays for a further 4 SATA drives.

Standard PC components are used throughout and it runs on a compact version of the Linux operating system, which resides on a 1Gb IDE flash drive module. This speeds up booting and frees up the drives for data storage. Video is recorded using the H.264 codec; it's a variant of the MPEG4 compression scheme that produces good quality images and small file sizes, so it is ideal for this application.

There's a range of resolutions, including CIF, 2CIF, 4CIF, DCIF and QCIF; motion sensing and camera sabotage recognition is available on all channels, there's the option to create privacy masks, and it has a wide range of display options plus a comprehensive set of search facilities and camera control functions. There are plenty more features but we'll deal with the more interesting ones as we come to them.

It's a fair old lump – the case is only 425mm wide but it's 445mm deep and with all of the connections adding another 50mm or so at the rear it might be difficult to accommodate in the space vacated by an old analogue VCR.

The front panel is divided into three sections. On the left is a fan intake and this opens to reveal a removable dust filter. The centre portion contains a backlit LCD mode/status display, a row of indicator lights and a USB socket and on the right there's another hinged flap. This one covers the two lockable HDD trays and the drawer for a slim, laptop-style DVD writer drive at the bottom.

Moving around to the rear of the case all of the video inputs, monitor outputs, alarm and a set of temperature sensor connections are on a single removable module, handy for upgrades, switching configuration, or swapping DVRs. Surprisingly there are no video loop through connections; this could be a limitation in some set-ups.

The only solution is to fit T-piece connectors to the inputs and switch off input termination in the setup menu. It may just about be possible on an 8-channel machine but it would be near impossible to fit more than one row of T-piece connectors to the 24-channel model we've been looking at.

Beneath the video/alarm panel is a more or less standard PC motherboard connector panel, for the monitor, mouse, keyboard, USB, parallel port, LAN and audio. In the centre of the back panel an 'Eject' button releases the video input panel and to the right of that are the backpanes for the motherboard expansion cards.

From left to right they are secondary audio and monitor outputs, a connection for the optional DAS-4 Eco external HDD storage unit, and a row of three cards with 15-pin D-Sub sockets for the audio inputs. Three D-Sub to phono adaptor cables are supplied with the unit (for 24-channel models). On the far right there's a connector socket for 12 volt DC out, used to supply the external storage unit, the mains socket and main on/off switch.

Inside the case the motherboard occupies the rear section with the drive bays, and various fans dotted around the front section. Build quality is most impressive and small but important little touches, like sealing drive cables in position with silicon mastic, should ensure a decent service life.

Setup and operation

Moments after switch on the machine boots to a Linux loading screen, dedicated to Leonardo da Vinci, whose 'pioneering and boundary-transcending inventions' are a source of inspiration for Dallmeier...

After a minute or so the main screen appears on the PC monitor showing one or more connected cameras. The camera display is duplicated on the video monitor outputs, though without the toolbar or mouse pointer, which is used to change the display configuration (sequence, single, quad, 3 x 3, 4 x 4, 5 x 5 or 12 + 1) or tap in the login to penetrate deeper into the menus.

The networking facilities of Dallmeier's DMS 240 DVR could make it a real winner...

To go any further it is necessary to logon to the system and once the password has been entered the screen changes to a desktop showing live images with toolbars along the top and bottom edges of the screen. The one at the top has buttons for the setup menus, import function, sequencer and shut down commands. The tool bars at the bottom of the screen are concerned with screen layout, camera selection and playback control.

Initial configuration is carried out from the Setup menu and this opens with four options: Recording, Network, System and Interfaces. The Recording menu leads to a number of sub-menus. The first one, Camera Settings, covers resolution, bit rate, frame rate, storage settings, with an estimate of available recording time and switches for enabling motion detection and camera control.

The next two, Camera Timer and Tracks Timer, are used to set up recording schedules for each camera and recording channel. VMD Areas handles motion detection configuration and Privacy masks, which are 'drawn' by dragging and dropping rectangular shapes, defined by the mouse pointer. It looks reasonably intuitive but this was one of the few areas where we had to resort to the manuals, particularly when it came to editing or removing a previously set motion or privacy target. By current standards the motion detection system is fairly basic and the only options are to change the size and shape of the target area.

HDD Management displays hard disk and external storage device parameters, and the Search Centre sets the criteria for the database oriented search system. Unfortunately this part of the menu system appears to have been overlooked during the translation and required some knowledge of German in order to make sense of it. Finally, the Camera Descriptions menu, which is used to compose camera titles using an on-screen keyboard. Again our sample, which appears to be using an early pre-release firmware, was less than cooperative when it came to making changes, but assuming it will be fixed, it all seems to be very straightforward.

Network on the setup menu opens with three sub-menus for setting network parameters, alarm hosts (presumably recipients of alarm messages) and Import/Export functions, however, there's little mention of it in the manuals and either this is a work in progress, or it will be dealt with in greater depth in the new manuals. We certainly hope so.

The System Menu is mainly concerned with housekeeping functions and a series of sub menus deals with display layout, user management (passwords and permissions etc.), Service Mode, System Info, Time and Date setting, System logs, System Security, user display language (German, English, French, Spanish, Italian), Downloads, Alarm options, System Parameters (importing and exporting settings), Camera Termination and Reboot. The final button, Interfaces, is for setting up the various ports, connections and communications with the outside world.

Fortunately basic operation is reasonably painless and most routine functions are easy to access. Clicking the Search button brings up a tabbed menu with options to carry out a 'Simple' search by time and date, a 'Quick' search, by time intervals, 'Index' search, by events, 'Extended' search, by Account or Transaction numbers and SmartFinder, which searches for objects or patterns in the image.

The Search Playback screen provides plenty of visual cues including clear time and date displays, easy to use controls, and a handy Timeline slider for quickly moving to any part of a recording.

Performance

As usual we'll begin with images recorded at the highest quality and frame rate settings and although these are unlikely to be used in the real world, due to storage constraints, they do give us a good idea of what the system is capable of. The results are impressive, using 4CIF/2Mb/12fps the image is a good size, colours are clean, noise levels are negligible and the image is packed with fine detail.

Stepping down to 2CIF results in only a very small reduction in quality and this setting also produces better still frame and slomo replay, particularly where there is a lot of movement in the scene.

Below 2CIF the image starts to degrade noticeably and the trade-off for extended recording times is a big reduction in resolution with increasingly ragged vertical edges and smudgy colours. Nevertheless, when used with a good quality camera both CIF and DCIF modes are perfectly adequate for applications where it is more important to record activity, rather than fine detail.

Search functions and the playback controls are refreshingly easy to use though it could do with more forward and reverse fast picture search speeds. It has just one.

Audio recording is always welcome on a DVR but we are truly spoilt with the DMS-240's 24-channel sound. The quality is surprisingly good as well, and more than adequate for capturing speech and incidental sounds. There is some cost to recording times but it is unlikely that all channels would ever be used so the impact is likely to be negligible.

What the manufacturer says...

The DMS 240 is Dallmeier's response to the market's demand for the development of a recorder capable of delivering real time 24/7 continuous, high quality video and audio recording and transmission.

Central to the DMS concept is the utilisation of the H.264 compression standard. This enables the delivery of high quality video and audio on all channels and at all frame rates. With simultaneous real-time recording of video and audio for all camera inputs 100 per cent recording coverage of all subject activity is achievable.

The DMS 240 comes with a variable number of activated camera and audio inputs (8, 16 or 24) and variable hard disk capacity from 250 GB to 1 TB. The DMS 240 also offers simultaneous real-time split display of all cameras and replay of various channels in time split mode (4/8 cameras in real time, up to 16 cameras with reduced picture rate). Picture quality is excellent with up to 2 MBit per camera and different bit and frame rates (Dual Stream) can be selected for recording and transmission.

All Dallmeier recorders are fully networkable. In addition the DMS 240 offers real-time split functionality as network operable whether via LAN/WAN, GSM/GPRS/UMTS or Internet (PView/Browser/PRemote). Multi-users are accommodated through multicast/unicast network streaming. Alarm messages can be sent by email or SMS.

The DMS 240 provides hard disk flexibility by two slide-in bays that can accommodate a maximum of two 500 GB HDDs at present. If higher storage capacities are required, the new DAS 4 ECO storage facility with four additional hard disk slide-in units with direct power supply over the DMS 240 can be used. Thus the total capacity increases with 500 GB hard disks to 3 TB.