The panel you choose for the bus, not for the keypad.

MAP 5000 is Bosch's upper range in intruder detection. «Modular» means the box does not set the size: you start with what you need and add modules and detectors on the same cable. Below it the house has families for small and medium installations, which are another conversation and another budget.

It turns up where there is floor area and shifts: a logistics unit working at night, a data centre, a bank head office, a museum, a building with floors let to different companies. The common trait is not the sector: it is that there is more than one schedule in the same building and you have to be able to arm one part while work carries on in the other.

The detectors do not run one by one back to the panel. They go on an addressable bus where every element has its number and answers by name. That changes two practical things: it saves an enormous amount of cable, and when something fails the panel does not say «zone 14», it says which specific element and whether what it has is an alarm, a tamper or a fault.

The bus can be cabled open or closed in a ring back to the panel. Closed costs metres of cable and is the difference between losing half a building and losing nothing: if somebody cuts it at one point, the ring carries on reading from the other side. An open bus with forty detectors in series and no sectioning goes down from the cut to the end, and what is behind stops existing for the panel. It is the decision most often trimmed when a quotation is tightened up and the one that costs most on the day there is a rodent in a cable tray.

The rest is what you would expect at this size. Independent areas, each with its own arming, its own schedule and its own people. Keypads that say in words which zone is stopping it arming, which is what saves the eleven o'clock phone call. Supervised power supply with batteries sized by calculation and not «whatever fits in the box». And transmission to the alarm receiving centre over the network with a second route over the mobile network, both supervised: a route nobody watches is discovered to be down on the day it is needed. With video or access from other brands it is resolved in software where the piece exists and with contacts where it is enough for one thing to let the other know.

What the equipment brings does work: dual-technology detectors requiring the infrared and the microwave to see the same thing before firing; anti-masking, which is a detector inside the detector watching whether somebody covers or paints the lens, and which reports it as a fault instead of going blind in silence; pulse counting and sensitivity per point; confirmation between two zones within a time window before treating the alert as a confirmed intrusion; and automatic exclusion of the zone that fires over and over on the same night.

Now the other side. Most of the false alarms we have been out to resolve came from the fitting, not from the brand. A microwave detector looking at a plasterboard partition sees what is happening behind it, because the microwave goes through the board — and behind it there is a forklift working at night. An infrared beam facing a west-facing metal shutter fires at dusk, when the sheet cools in gusts. And a detector giving a masking fault every morning at six is not broken: it is that at six somebody parks a pallet in front of it. And the zone under building work is isolated on paper —what was isolated, who authorised it and on what date it comes back—, because whatever is inhibited «until they finish» stays inhibited for two years.

The European standards classify alarm systems into security grades according to the risk and the class of intruder expected, and each grade demands things of the equipment, the cabling, the power supply, the tamper detection and the supervision of the transmission route. The grade is set by the activity, very often by the insurance and sometimes by a specification. And there are two things quotations mix up: equipment certified for a grade is not an installation that meets that grade. A panel in this range gives you room to design high; what grade is handed over is stated by the design and signed by whoever hands it over, on paper and with a date. Ask for it, from us as well.

Connecting to an alarm receiving centre is another decision, with its own contract and its own regulations. In Spain the receiving centre is obliged to verify the alert before passing it to the State security forces, and there verification by image stops being an extra and becomes the piece that makes the system worth anything.

It fits where there are many points, several areas with different schedules and somebody who is going to ask for traceability: who armed, who disarmed and which zone stopped it arming. It fits particularly well if the video and the access already come from this house, because then the single screen is not a sales argument but a fact. And it fits where the risk calls for designing high: rings, fine supervision and a dual transmission route.

It does not fit an industrial unit with twelve zones, one schedule and nobody to administer anything: it is too big and it costs more than it needs to. Nor if what you want is to fit it tomorrow, because this is designed, cabled and documented, and that time is part of the product. And if the budget covers the panel but not the ring, the real autonomy and the maintenance, the upper range is an ornament: better a more modest one fitted well than this one done halfway.

The client runs without difficulty the users and codes, who can arm which area, the automatic arming schedules, isolating a zone when there is building work or a fault, and reading the log. A panel in this range has permission levels, so you can give somebody user management without giving them the configuration: whoever adds a new worker has no need to be able to change what a zone does. And named users from day one, because a log saying «user 1» disarmed says nothing.

What needs the installer is whatever changes the behaviour or affects the paperwork: adding or removing elements from the bus, changing entry and exit times, touching the sensitivity or the confirmation logic, redoing the tree of areas, altering the transmission routes and upgrading versions. There are two reasons and both are good: a mistake there is not noticed until the day the alarm is needed, and if the installation was handed over with a grade, touching that without redoing the documentation leaves it lying.

And two things are needed that are handed over and charged for. Training by role: whoever arms each day, whoever manages users, and whoever decides in the small hours. And documentation worth having: a drawing with every detector and its address on the bus, areas and schedules exactly as they ended up, who receives which alert and in what order, and one sheet with the five problems that are going to happen. A system only one person knows how to handle breaks the day that person goes on holiday.