MP500/4N-8-16 Installation
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4.2.3 Sizing the power supply and data transmission bus
The bus connects the various devices and guarantees their power supply and data transmission. The total length of the bus must be as
short as possible and, in any case
the extension, that is the sum of all the stretches of bus must not exceed 400 metres
.
In order to reach this result, and facilitate the wiring work, in the creation of the system any of the topologies illustrated here below can
be used freely.
Figure 10 - Topologies of the bus connection
IMPORTANT!
Do not create closed rings with the bus to prevent malfunctions.
Figure 11 - Rings on the bus
It is not necessary to tend the bus line and each individual stretch (as typically occurs instead with the RS485 type).
In the bus, the sizing calculation for the cables is carried out only to determine the size of the power supply cables “
+
” and “
–
".
4.2.4 Extending the bus with the repeater
The 400-metre length limit of the bus can be overcome with the use of the AS500/RPT supplementary power supply unit.
Indeed AS500/RPT power supplies, in fact, in addition to serving as supplementary power supplies, they make the repeater func tion
available.
IMPORTANT!
The supplementary power supply with repeater AS500/RPT can only be used with the MP500/8 and MP500/16
systems.
When using the repeater with the MP500/8 and MP500/16 control panels, always follow 3 simple rules.
The maximum number of repeaters allowed is 15.
The length of the stretches of each secondary bus cannot exceed 400 metres.
It is not possible to connect two or more repeaters .
Below are some examples of how to use the repeater.
In the example, it is possible to see the primary bus with the bus that exits directly from the control panel, with the secondary bus
deriving from the repeaters.
