Ultrabus serial line, former "RS‑485" serial line, allows the communication between the unit and compatible devices without limiting the communication only to alarm and fault conditions ensured by traditional wired connections.
For example, it will be possible to setup the device or update device firmware directly using unit configuration software, without the need to go to the device to adjust jumpers or dip switches position.
Devices connection to Ultrabus line
A device that can be connecte to the Ultrabus line (included the unit) has four terminals, usually with "RS‑485" or "ULTRABUS" printed.
- Starting from one line end, connect each terminal with the corresponding terminal of the following device.
- On the first and last device, connect a 680 Ω end-of-line resistance between terminals A and B.
- Connect unit GND terminal with cables shield.
Max length of the line is 1 km.
The procedure described above allows to create a serial line without branches.
It is also possible to create one branch or more by connecting, for example, a device four terminals to the corresponding teminals of 3/4 different devices.
The number of branches that can be created is virtually endless but the total length of the branches must be max 1 km.
Connect end-of-line resistances only to the last device of the two longer branches.
RPX485 repeater modules can be used to extend line length further.
The module connects to a Ultrabus line like any other compatible device and has a second terminals set to which a separated Ultrabus serial line can be connected.
Such serial line has the same features as the main one:
- Supports Y connections.
- The sum of branches length cannot be longer than 1 km.
- RPX485 device shall be connected to one of the two longer branches.
Connect RPX485 repeater to a Ultrabus serial line to which has been connected...
- the control unit, or
- a repeater complying with the previous point (such setup is not available for ETR units with firmware 1.7 or below).
ETR100M ETR G2 NET PREGIO500 PREGIO1000 PREGIO1000BM PREGIO2000 TITANIAPLUS VIDOMO VIDOMO2K VILLEGGIO VILLEGGIO NG‑TRX RS‑485 RS485 ULTRABUS