Ask for a detailed explanation of the multi wire system and the bus system in the fire alarm system

I'm from the electronics side of your multi-wire and bus system problem :

1. They all refer to the wiring method of the fire alarm system.

2. Before about 1998, the fire alarm system had N+1 wire system (before 1994), 4 bus, 3 bus, etc., which were cumbersome and costly.

3. With the development of information technology, around 1998, there was a 2 bus mode, which provided power to the detector (usually: smoke sensor, temperature sensor, etc.) alarm button (usually: manual alarm button, fire hydrant alarm button, etc.) by two wires, and at the same time, the information wave was loaded on the detector and button through the line, so as to realize the collection of the normal, fault, fire alarm and other states of these detectors.

Due to the advantages of convenient maintenance, construction, economy, signal stability, etc., the current fire alarm system has all adopted the two-bus system.

You can take a look at the call display in the corridor of the hospital ward building, and notice that it only has 2 wires connected, but it can not only display the time, but also display the call signal of any bed——— right, this is called the bus system!

In the fire alarm system, the way of controlling the linkage of equipment is divided into bus system and multi-wire system.

Bus control is module control, and the 24V power supply signal or switching signal required for equipment action is provided by the bus module, which is usually used for less important equipment linkage; The advantage is that the wiring construction is convenient and the cost is lower, and the disadvantage is that the reliability is not as good as that of multi-line.

Multi-line control is direct control, and the signal is manually or linked output by the alarm host, which is directly provided to the equipment; It is used for the control of key equipment; The advantage is high reliability and good stability, and the disadvantage is that the construction workload is large and the cost is high.

The fire alarm system is generally composed of the following parts:

Alarm section. Detectors (usually: smoke, temperature, etc.).

Alarm button (usually: manual alarm button, fire hydrant alarm button, etc.) fire linkage part (usually: fire pump, sprinkler pump, fan, tuyere, electricity, etc.) fire alarm part is generally controlled by bus, and fire linkage part can be controlled by bus or multi-line (generally used).

Fire (automatic) fire extinguishing systems are now water systems (generally sprinkler systems; special deluge system) and inert gas system to extinguish the fire. The general fire extinguishing system is a fire hydrant system.

The fire linkage system refers to a series of actions commanded by the fire engine to carry out when a fire occurs. For example: fire pump start, smoke exhaust fan start, positive pressure fan start, smoke exhaust tuyere open, positive pressure tuyere open, exhaust tuyere closed, power cut-off, etc.

1. What are the general components of the fire alarm system?

Answer: It is mainly composed of two parts: alarm and linkage.

The alarm part is now generally used in the bus system, and the linkage can be bus or multi-line.

2. What is the linkage system?

Answer: Linkage means that in the event of a fire, the alarm controller or linkage controller controls the field equipment. For example: turn on the exhaust air (linked by the alarm controller bus) and start the fire pump (multi-line linkage by the linkage controller).

1. The cost is different.

The bus system saves wiring and cost in terms of layout, and the cost is lower, while the multi-wire system is more cumbersome and cost-effective in terms of layout.

2. The input mode of the detection signal is different from that of the controller.

The multi-wire detectors (devices) are independent of each other, and all detection signals are input in parallel to the controller. In layman's terms, it is a point-to-point connection. The bus system means that all detectors (devices) are connected to the bus in parallel, and all detection signals are serial communication with the controller.

Each detector (device) has its own unique address code.

3. Reliability is different.

Multi-line control is direct control, and the signal is manually or linked output by the alarm host, which is directly provided to the equipment; It is used for key equipment with high control reliability and good stability; The bus system, on the other hand, is usually used for less important device linkage and is slightly less reliable.

1. The bus loop contains detectors, hand reports, sound and light and modules, etc., that is, the total number of addresses in a loop does not exceed 200.

2. The number of modules in the linkage bus circuit shall not exceed 100.

Today's fire alarm controllers are generally linkage type, which means that the number of modules in a circuit should not exceed 100.

To understand the alarm host of the bus system, we must first understand the alarm host of the split line system. The split-line alarm host is the front end.

The switch signal of the detection device is directly on the host defense area to trigger the alarm host alarm, and these switch signals must pass through two.

The cables are connected to the defense area port of the alarm host, and each wired explorer needs to connect the signal line to the branch host. His knots.

The structure is simple, and the number of defense zones is relatively small, that is, how many pairs of cables are needed for as many detectors (defense zones) as there are.

The bus alarm host is different, it is to connect the front-end detector to the switch signal in the address module (or alarm module).

On the defense area extension module) bus, when the detection equipment of a defense area finds that someone has entered the illegal entry, the detector sends an alarm signal, and the address module (or called the alarm module, the defense area extension horizontal block) is transmitted to the alarm host through the data bus, and the defense is real-time.

The alarm signal and alarm type in the fan area are displayed on the keyboard of the alarm host. and trigger the sound and light alarm, so that the operator can be timely

Accurately cover the police situation and mobilize security personnel to deal with it in a timely manner. The structure is more complex, but there are more defense areas that can be accommodated.

In this way, there is no need for a pair of probes to pull a pair of signal lines to the host, as long as the address module is connected, the distance between the address module and the host can reach 100 meters, and a pair of signal buses can be connected to up to 248 address modules (or called.

Alarm module, anti-zone extension cross-section).The address module can be connected to 8 defense zones. If you have more defense zone teaching, defense.

If there are many areas and are more complicated, it is better to use the alarm host of the bus system. Because in this way, the wire and manpower are greatly saved.

cost, construction is very convenient.

In short: the bus host is to use a 2-core wire to transmit the signal of multiple defense zones and multiple probes, and the bus is like a wire, and the probe can be connected to more than one.

Each defense zone of the split-line host must be connected with a 2-core cable separately: the split-line is like a network cable, and each computer must have a separate one.

Now the alarm system of each manufacturer adopts the wiring method of two bus systems, that is, multiple alarm devices (smoke detector, temperature sensor, hand report, etc.) can be connected in parallel on the two lines according to the different circuit capacity of each manufacturer, and the maximum number of equipment connected by these two lines may not be the same (for example: the bay circuit capacity is 242 points, and other manufacturers have 96 points, and there are 256 points, etc.).

The multi-line system is for the bus system, our national fire code has provisions, for some important equipment (such as: fire hydrant pump, sprinkler pump, smoke exhaust machine, etc.) must be controlled by the multi-line system, that is, each equipment must have a separate control line connected with the fire host, so that even if the line of a certain equipment is faulty or shortened by fire, it will not affect the use of other equipment.

Advantages of bus wiring mode: simple wiring, convenient construction, low project cost Disadvantages: once there is a problem with a certain line, it may affect the equipment on a section of the line (or the entire circuit) can not work normally.

Advantages of multi-wire system: problems with one line will not affect the normal operation of other equipmentDisadvantages: complex wiring and high project cost.

The main differences between the bus system manual control panel and the multi-wire system manual control panel are: 1. It adopts separate wiring, or the same signal bus as other field equipment; 2. The other is that the leased line disk is not affected by the host status.

The manual control panel of the bus system is to define the address of the control equipment module carried on the signal bus to any address on the bus panel, and control the field equipment through the bus panel, such as rolling shutter doors, sound and light alarms, etc.

The multi-wire manual control panel is mainly for special line control of important fire-fighting equipment such as fans, pumps, etc., and each equipment is wired separately to the site to ensure that the controller can start the field equipment in the control center in any state (normal or faulty).

Multi-line control and bus control have corresponding multi-line control panel and bus control panel. Multi-line control is also called direct control, that is, the use of multi-line module directly to the control equipment, the general multi-line control point is to control the fire pump, fan and other equipment, multi-line control module is not a coding point.

The bus control is connected to the controlled equipment by the input and output module connected to the loop, and there is a bus control point on the host, and the control point and the corresponding equipment can be set in the software, and the bus control equipment can also participate in the automatic linkage and write into the linkage program.