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Offline controllers - are you missing out?

The most successful of our resellers think laterally. The queue, selling standard commodities, or in our case standard solutions, is long and competitive. Winning orders comes from applying the thought process to existing clients using proven existing technology – albeit in a slightly different way.

Technology designed in the second millennium should incorporate tools that enable you to deliver, from a single platform, far more than the single dimensional thinking of the '90s. Below is an example of how to utilise existing product knowledge in new applications.

It was almost three years ago when I overheard one of our resellers explaining how he had received an order to install a high security perimeter project, involving:

* High walls.

* Wall top zoned alarmed electric fencing.

* 'no mans land' corridors.

* IR Beams for 'no mans land' intrusion detection.

* Zone based alarmed floodlights.

* Zone based corridor CCTV.

* Building based alarm and panic systems.

* Display to be hard wired mimic with simple but clear system status display.

* Automatic 'low battery', 'low diesel' type alarms sent to the control centre.

* Complex inbuilt checks and balances to prove the system was in full operational condition.

* A full audit trail for post incident analysis.

* No PCs on site - hardware reliability only.

* Minimal user intervention.

It was recommended that the ImproX be employed and three years later, the system is still going strong.

The solution

The Improx and Impronet system includes controllers that do not need any communication with the host PC until new instructions are required to be downloaded. The controllers can therefore theoretically stay off-line for years. This principle of having controllers in the field is commonly known as 'distributed processing'.

Secondly, the terminals in the system include a vast array of readers (prox, mag, bar code, RF, IR and biometric), as well as various types of digital I/O, Wiegand, RS232 and 3rd party interface terminals.

It was decided to put the I/O terminals to the test.

Hardware layout

Firstly, an IXP 400 controller had to be mounted somewhere safe (in a weatherproof housing) in the control centre. Thereafter, it was a matter of adding up the necessary inputs and outputs required at any point in the system, eg:

In the field housing at each energiser point, one would need (eg zone 2):

* Input x 1 - Z2 fence low voltage alarm

* Input x 1 - Z2 fence trigger alarm

* Input x 1 - Z2 fence alarm reset button - situated in the field to force physical inspection by guards.

* Input x 1 - Z2 - IR beam trigger alarm.

* Output x 1 - switch Z2 perimeter lighting.

The Improx DR unit was well suited, consisting of a single box with 4 inputs + 4 relay outputs. All of the field units would be connected on a bus via single pair screened twisted data cable.

The head end would consist of something similar, except that the mimic switching would require quite a few additional output relays. For this purpose, we made use of one Improx O16 device and one Improx DR. Each Relay on the O16 was connected to one LED on the mimic panel, as well as the mimic buzzer and alarm siren.

The inputs on the DR were used for buzzer acknowledgement, lamp test, gate opening, etc. By connecting the gate via the I/O meant that each transaction was recorded and view, later if required.

Mimic panel

While a mosaic mimic panel would have worked well, it was decided to ask a screen-printing company to match the site layout and colours directly onto PVC. There was some work to do drilling the holes and mounting the LEDs, but connecting them into the O16 units was relatively simple.

Software setup

In the past one would have asked a scada or PLC company to quote on the hardware. This would have required relatively expensive hardware, as well as custom written software. In this case, the software setup was given to a hardware technician who had relatively little experience with Impronet. By utilising the standard features in the standard access control software, the technician emerged at the end of the day with a fully operational system.

On-site setup

Although the setup could have been downloaded to the controllers back in the office, it was decided to take the PC out to site, just in case a few last minute 'tweaks' were required. Following a few amendments to parameters (normally open (N/O) to N/C and relay closing time adjustments), the PC was unplugged and removed back to the office. The Impronet database (containing the system setups) was copied to CD and filed.

There have been no malfunctions from the system since installation three years ago. Following this, two of Impro's other resellers have taken the lead and installed similar systems for the SA Prison Services. Not all have opted for the pure hardware option, but have instead gone for the live graphics software to graphically display, on a computer network, fence alarms as they occur. This also has the benefit of time and date stamping operator responses to alarms. These systems are still operating to full specification.

Key to this system

The key is to have at the core a controller that is open enough to receive input signals and make output decisions. This of course is the IXP400 controller which:

* Can handle 64 terminal devices on an RS485 bus.

* Each terminal can accommodate up to 16 output relays or 16 digital inputs.

* Is essentially 'event and action' based to allow for user defined configuration.

* The controller installed could store the last 30 000 transactions, however, by simply adding more memory modules the figure can be increased up to 500 000 transactions.

* Can switch any predetermined system output based on any predetermined input.

* Can be run from software (a PC) if and when required.

* Is 'off the shelf' standard with easily obtainable spares, upgrades and training.

Versatility is a key to product success, whilst a hard look at your own thought processes are equally critical to success in this demanding environment.

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