What our experts say …
If there is one thing most installers dread it is messing around with a dead camera on the top of a 20-foot pole or some even more treacherous location. Add in the British weather and the fact that there will probably be nothing wrong with the camera (and the fault will always be in the last place checked), and you have a very convincing argument for a product such as the Pelco ES31C, a rugged and fully integrated motorised camera system from a company with an impeccable pedigree and track record for dependability.
The key word is ‘integrated’ which rightly suggests that the camera, its motorised mount hardware and associated systems are all designed from the ground up to work together. This has major implications for ease of installation, configuration and long-term reliability.
That is not meant to imply that motorised camera systems assembled from components made by different manufacturers are inherently less reliable. But there is a good chance installation times will be longer and control systems will necessarily be more complex, or less flexible, or both.
The EC31C is a member of Pelco’s Esprit family. It is rather grandly described as a ‘Positioning System with IOP’ (Integrated Optics Package), otherwise known as a pan/tilt head with built-in camera and lens. The model we looked at is the ES31CBW18, which is the top-of-the-range version with a high resolution colour camera featuring an 18x optical zoom and 4x electronic zoom plus a built-in window wiper; other models are also available.
Starting with the camera section specs, our sample has a F1.4 lens with a 4.1 – 73.8mm focal length. Low light sensitivity is quoted as 0.2 lux (slow shutter mode); the 0.25-inch interline CCD, has a 752 x 582 pixel array giving a claimed resolution of around 460 lines. Focus, exposure shutter speed and white balance are fully automatic (with manual overrides).
The camera is remotely configurable via a menu-driven on-screen display system. The main options are auto focus on/off, auto iris (auto/manual, iris level & peak level), switchable IR filter and level backlight compensation with adjustable sensitivity area and variable gain/AGC. Picture sharpness and shutter speed can also be manually adjusted.
The on-screen displays also cover programming the motorised head functions and positioning. The front window has a built-in heater/de-mister and the whole caboodle is powered by an external 24v AC supply. 120/230v models are also available.
The imposing and very sleek looking pan/tilt assembly has an equally impressive specification. Pan speed is variable, between 0.1 and 40 degrees per second variable speed and 100 deg/sec in ‘turbo’ mode, with proportional pan and 360 degrees rotation. Vertical tilt is from -90 to +40 degrees at 0.1 – 20 deg/sec variable speed. Preset pan/tilt speeds are 100 and 30 deg/sec respectively.
General operating parameters are a safe temperature range of -45 to 50 degrees centigrade (60 deg C tolerable for short periods) and it will remain operational in wind speeds up to 90mph and withstand up to 130mph, though whether or not whatever it is bolted to will stay upright in such conditions is open to debate.
Camera set-up and the motorised mount functions can be controlled and programmed using a wide range of Pelco system components: video switcher/controllers CM6700/8500/9500 & 9760 and keyboard units KBD200/3000 & 300V. Our review sample was used with a CM6700 matrix camera switcher and KBD300 Universal keyboard.
The EC31 can communicate with its control hardware using either RS-422/RS-485 protocols, or Pelco’s proprietary Coaxitron system, which uses the video connection to carry telemetry and data to and from the camera.
The standard of construction is high. The camera housing is made from heavy gauge die cast and sheet alloy materials, the finish is very good indeed and it is clear that a lot of attention has been paid to weatherproofing.
Access to the camera’s innards is via a hinged, spring-loaded panel on the top. Once open the all-in one camera module or ‘sled’ can be easily lifted out with just one hand (worth knowing when you are perched on top of a ladder 30 feet above the ground).
The pan/tilt mechanism is superbly engineered and looks as though it will withstand just about anything the British climate (and vandals with good aim) can throw at it. It has two gearless drive trains, using toothed nylon belts, which undoubtedly contribute to its smoothness, quietness of operation and impressive turn of speed.
Camera and motor controls and the communications electronics are all mounted on a single PCB housed in one of the two side lobes. Re-fitting the covers and aligning the seals can be quite tricky, so it is a good idea to carry out any adjustments on the ground. (There is a pair of DIP switches for setting communications protocols.)
Installation is unlikely to pose too many problems for experienced engineers and, as with the rest of the unit, the mounting hardware is very well engineered, functional and easy to use. The same goes for the instructions, which appear to have been written by someone who actually knows what they are talking about.
The unit connects to the outside world using a single, small multi-way plug on the end of a flying lead emerging from the base of the pedestal; this mates with a socket mounted in the top of the transformer module, which once again contributes to easy installation and maintenance.
The remainder of the on-screen menus are mostly concerned with programming the unit’s motion and movements. The options include setting limit stops, tour pattern length (1.5, three or six minutes, or two half-patterns lasting 45 seconds, 1.5 or three minutes), action on power up (default configuration, park on preset 1, auto scan, random scan, full pattern, and half pattern 1 or 2). Panning motion can be set to normal or proportional, which means the pan speed slows down at higher zoom settings. Limits can be set on scanning speed (one to 40 deg/sec) and there is an option to reset the unit to its factory defaults.
A feature called speed profile allows the operator to adjust the unit’s behaviour in wind speeds of 50 or 90mph (sets limit on pan/tilt speeds at higher wind speeds), and there is a set of wiper adjustments (momentary wipe, variable dwell time and wipe duration).
Image quality is very good indeed and our sample performed at or close to the manufacturer’s specifications. Resolution was within a whisker of the stated figure and colour accuracy remained stable under mixed lighting and sudden changes in scene lighting. In low light conditions the camera automatically switches to black and white mode and it continues to produce a useable image in quite difficult conditions. The electronic zoom takes over seamlessly when the optical zoom reaches the end of its travel. Noise levels in all operating modes are below average.
What the manufacturer says …
The ES31C is an innovative addition to the product line of Esprit Series Integrated Positioning Systems. It not only combines a receiver, pan & tilt and enclosure in a single easy-to-install system, it also includes an Integrated Optics Package, which contains an auto-focus camera and lens module with programmable features.
For a wide range of applications, the ES31C Series features a choice of three IOP cameras: a colour camera (380 TVL) with a 128X zoom lens, a high-resolution camera with LowLight colour technology and 176X zoom lens and a high-resolution colour/black & white camera with an infrared cut filter and 72X zoom lens. A powder-coated aluminium construction makes the ES31C ideal for indoor or outdoor applications. The system has an absolute operating temperature range of -45 to 60 deg C. Also included is a window wiper, completely integrated into the enclosure and does not interfere with the viewing range. The wiper can be programmed to delay between wipes and to automatically shut off.
The variable pan and tilt speeds range from 0.1 to 40 deg/sec in manual pan mode and 0.1 to 20 deg/sec in manual tilt. Pan preset and turbo speeds are 100 deg/sec in wind speeds of 50mph and 50 deg/sec in the 90 mph wind-speed profile. The model is capable of 360 deg of continuous pan rotation. The tilt range allows for horizontal viewing of +40 to -90 deg. There are 64 preset positions with a preset accuracy of one-quarter deg.
Pelco has three authorised distributors in the UK; PTS, Videor Technical and Richardson Electronics, who supplied the equipment for testing.
