Some facilities require more rigorous physical security needs, and your access control solution should be able to support these special applications. Here we cover how to install and configure the Verkada AC41 for man trap and in-out badging.
A man trap is a set of two doors where the first door must be closed before the second is permitted to open, similar to an airlock.
To support this, we must wire the doors to the AC41 in a specific way:
Figure 1: Wiring two doors to AC41 for man trap
By connecting the interior door's lock in series with the exterior door's contact switch, we do not allow the interior door to open until the exterior is closed.
Some doors have a card reader on both sides, and access needs to be controlled in either direction. We can accomplish this in one of two ways:
Option 1: Two Readers, Two Cassettes
Figure 2: In-out badging using two AC41 cassettes and fail-secure locking in dry configuration
Note: If using the configuration as shown in Figure 2 you will need to additionally configure the desired Aux Input to unlock the door that is connected to the lock. This article covers setting up that Aux Input.
Option 2: Optical Wiegand Isolator
Figure 5: In-out badging using an optical isolator
We can connect two readers to the same AC41 cassette using a Wiegand optical isolator. You will need to short the 5V resistors to each data line (orange lines). This saves a cassette, but requires another device and will not allow you to distinguish between interior and exterior access events.