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Bus overview, 1 bus overview, Bus systems – Siemens FC700A User Manual

Page 15

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Bus systems

15

Siemens Building Technologies

007836_a_en_--.doc

Fire & Security Products

03.2004


6.1 Bus

overview

Features C-Bus

I-Bus

SynoLOOP

SynoLINE600

LON-Bus

Data

Bus

Field of applica-
tion

Local system bus

Inside control unit

For addressable

detectors

For collective

detectors

Local data bus

for floor indicator

panels

Local data bus

parallel ind.

panel, synoptic

panel or relay

Speed of trans-
mission

57kBaud 1000kBaud

2

messages/sec

(Direct current

signal)

78kBaud SPI-Bus

2KHz

Length of line

Max. 1000m

(G51 ∅ 0,8: 1400m)

Max. 3m (only

inside cabinet)

Max. 150Ω/300nF

See chapter 16

Max.

150/250Ω/4µF

See chapter 16

Max. 500m as

free topology

Max. 1000m as

stub line

Max. 1000m

Number of users
connected or
addresses

… 16

C-Bus devices

… 16

I-Bus modules

… 128

D-Bus devices

1 address

(Max. 25 detec-

tors)

… 32

LON-Bus de-

vices

… 24

Max. 8 addresses

Number of wires

2

(+3 wires for emer-

gency operation)

26 2 2

2

6

(+3 wires supply)

Type of cable

Twisted 1)

Flat cable

Twisted

(Un-twisted per-

missible)

Twisted

(Un-twisted

permissible)

Twisted Twisted

Loop line

– – –

T-branch

– –

(See chapter 18)

Short-circuit proof

Yes

Each user con-

nected with line

separator

Yes

Each user con-

nected with line

separator

No No Yes

Network structure

Master/master Master/slave Master/slave

Master/slave Master/slave Master/slave

Scanning

Event-controlled,

presence monitoring

Cyclic,

Event controlled

Cyclic

- typ. all 64s
- Interrupt on
alarm

Event-controlled,

presence moni-

toring

(All 60s)

Cyclic

- typ. all 250ms

Principle

Serial Bus

- Cerberus protocol
- Collision detection
- Manchester coding

C-Bus

- Cerberus protocol
- SPI/Motorola

Sensor/actor-Bus

- Cerberus proto-
col 'K31'
- Serial 8bit
- Start-up: daisy-
chain

Conventional

- Current gain
principle
- Voltage levels

Network

- Echelon Chip
(LON protocol)
- Cerberus
specific telegram

Serial bus

- Cerberus proto-

col

1

Calibrated according to cable impedance: 50Ω (MICC) / 110Ω (G51, ø
0.8mm, not shielded)

6.2

Modifying the impedance of the various C-Bus cables

C-Bus standard cables have a characteristic impedance of 110Ω. The driver and
end-of-line resistors are soldered to solder lugs and can be adapted accordingly
with other characteristic impedances (see diagram chapter 6.2.1).
1. Explanation
A cable must be terminated with resistors. The resistance value must correspond
to the impedance of the cable. Each C-Bus user has four end-of-line resistors
(Ri)
. In addition two driver resistors (Rd) are integrated on the p.c.b. In order that
the resistors can be exchanged easily they are all soldered to solder lugs.

C-Bus p.c.b.

Ri

Rd

B3Q700

R31 ... R34

R49, R50

E3H020

R173, R174, R177, R178

R180, R183


The driver resistors specify the current on the C-Bus. In order that the signal on the
C-Bus always has the same amplitude (1.35Vpp), the following correlation is valid:

Rd = Ri x 3,65

(45Ω < Ri < 200Ω)