Overview Of Devices - Pyronix PCX 78 Installation Manual

Overview of Devices

All peripherals, such as LCD keypads, readers, expanders, are connected via the D1-, D2+, D3 and
D4 terminals.
Figure 1: Example of a typical PCX bus
General Principles
1. No alarm system cable should be run with other cables carrying AC or digital signals.
2. The cables should be protected by the use of grommets where appropriate.
3. For greater than 1000m range, standard isolated RS485 repeaters are required.
4. There must be a ferrite bead fitted to one of the outgoing data lines and secured inside the
PCX case itself. The Ferrite bead is supplied packaged with a cable-tie which must be used
to secure it in the case and prevent it shorting any electrical contacts (Ferrite as shown).
There must also be a ferrite bead fitted to the data wires of a PCX-EXT-BK/W (if connected).
The Ferrite bead is supplied with the reader.
12 PCX Installation Guide 102017852 - V01