What's in an APC Hub and Why should I buy it?

Bulletin Number: 157
Released By: Don Stauffer
Product Family: APC SYSTEM
Date: 8/8/2013
Classification: Sales Advisory

The Leprecon APC system is a simple, DMX based panel system that integrates easily with DMX control desks.

As a specifier or installer, why do I need the 'APC Hub' to power these panels, they only require 12VDC, right?

The answer is that the hub serves several important functions in the APC system.

1. Yes, the 12VDC power supply is located in the hub. It serves to power all panels in the system.
2. The Hub provides an interconnect point for console DMX (5 pin female XLR), DMX out to the system (5 pin male XLR) and the wall panels (RJ45). These three connectors must be wired together properly for the system to work, and the Hub does this for you.
3. The hub provides DMX isolation and buffering. Signal out to the lighting system is not loaded by any of the panels or wiring up to the hub.
4. The industry is flooded with inexpensive offshore DMX fixtures these days. Often these devices are not truly compliant with the DMX specification. The Hub provides several levels of 'DMX Deceleration' that helps ensure a properly working sytem.
5. APC panels communicate with each other using DMX 'reserved start codes'. These codes are part of the DMX specification. As with item 4, some poorly designed gear cannot cope with 'reserved start codes'. The Hub removes these codes before sending data to the lighting fixtures, another way of working around flaws in low cost fixtures.

If you install an APC system without a Hub, you will have to solve problems 1 and 2 in some creative fashion, and problems 3, 4, and 5 are potential issues that could show up now or in the future.