The Honeywell 4208U Universal Zone Expansion Module allows a user to set up eight additional hardwired zones on their system. This module is for commercial polling loop panels only. Any hardwired sensor that is connected through the 4208U will communicate through the panel's polling loop.
Without any zone expanders, a VISTA-128BPT or VISTA-250BPT can only support a very small number of hardwired zones through its on-board terminals. To get the most out of these systems, you will certainly need to add a few zone expanders. Please note that the 4208U will only work with commercial polling loop panels, and it is not compatible with the non-polling loop panels.
The advantage to wiring through the polling loop is that it provides the user with more flexible wiring options. Non-polling loop panels use the keypad bus for expansion. The keypad bus has a much shorter wiring limit of 1,500 to 2,000 feet depending upon the panel. The polling loop, on the other hand, has a limit of up to 12,000 feet. The 4208U only requires two wires to connect with the main alarm system. This is unlike non-polling loop expanders (which won't work with the polling loop systems) that require four wires to connect with the system.
The 4208U is considered universal because it can work with panels that support serial number programming, as well as older panels that use dip switch programming. Both dip switch and serial number programming can be used with the 4208U module. But by supporting both serial number and dip switch programming, it limits the number of unique identifiers that can be used with 4208U modules. As a result, users should keep in mind the number of available zones on their system before adding any 4208U expanders.
The 4208U is only capable of adding up to 128 zones with unique serial numbers, which is the equivalent to 16 modules. This will work just fine for a Honeywell VISTA-128BPT. However, the VISTA-250BPT can support up to 250 zones. So if a user wants to maximize the zone capabilities of their VISTA-250BPT, they will need to use zone expanders that only support serial number programming instead. We recommend the Honeywell 4208SN for this purpose. Of course, the 4208U will still work with the 250BPT if the user is able to keep their hardwired zone count under 128. And the advantage to the 4208U over the 4208SN is that it is supported by older panels that cannot utilize serial number programming.
Please note that no wiring comes included with the 4208U module. A user will need to add their own wiring in order to connect hardwired sensors with the expander. The user will also require wiring to connect the 4208U with the system itself.