A Vista 128 loop (specifically on the Honeywell/Resideo VISTA-128BPT commercial alarm panel) refers to the polling loop (also called a V-PLEX or multiplex loop) or a device loop number used to connect and address expansion sensors.
The Polling Loop (V-PLEX)
- What it is: A built-in two-wire multiplex communication bus on the VISTA-128BPT panel (wired to terminals 24 and 25).
- Capacity: It supports up to 119 additional expansion zones (on top of the 9 hardwired style-B zones) using specialized addressable devices.
- Compatibility: You cannot wire standard conventional sensors directly to this loop. You must use V-PLEX (polling loop) addressable devices or expander modules like the 4297 Polling Loop Extender.
- Power & Distance: It provides up to 128mA of operating current and can run up to 12,000 feet depending on wire gauge and shield usage
Zone Loop Numbers
- What it is: A loop number is a specific input channel on a serialized V-PLEX device.
- Why it matters: A single physical device with one unique serial number can feature multiple input terminals or contacts (for example, a multi-zone expander or contact with an auxiliary input).
- Programming: When you program the device into the panel via menu-field
*93, you assign a specific loop number (e.g., Loop 1, Loop 2) to tell the panel which input channel corresponds to which system zone
Added by Google Gemini