The Verkada access door controllers are capable of supporting Verkada readers over RS-485 and standard Wiegand readers. The following diagram shows the wire types and max lengths that are recommended for use with the Verkada AC41 and AX11.
We recommend using one twisted pair for - (ground) and + (power) and one twisted pair for the data (D0/D1, in the case of a Wiegand reader, or A/B, in the case of a Verkada Reader).
Access control combo/trunk cabling may be used, as long as each individual cable is shielded and the proper gauge.
It is REQUIRED to use ONLY shielded cabling for all inputs on the AC41 and AX11 (i.e. all components connected to the access controller, including the locks, must be connected with shielded cabling). Failure to use shielded wiring and to ground it properly may result in poor reader performance or even damage to the access controller.
You can tell your cable is shielded if it has a metallic foil surrounding the wires and a bare metal drain wire.
For a properly grounded installation, connect the drain (bare metal) wire from the reader to the drain (bare metal) wire in the cabling. Then, connect the drain wire in the cabling to earth ground.
Ideally, your connection to ground should be near the reader. Some examples of ground points include a grounded junction box or door frame. If you do not have a way to ground the drain wire at the reader, you may connect the ground at the access controller using a grounded junction box, grounding busbar, or the negative battery terminal of the access controller. If you are using a battery, you can splice the connection (i.e. one connection to the battery and another to the drain wire).
This diagram provides an example of how the drain wire might be connected to the AC41's negative (black) battery terminal. The red wire represents the positive battery terminal and the pink wire represents the bare metal drain wire. The AC41 on the left has the drain wire directly connected to the black battery wire. The AC41 on the right shows the drain wire connecting to the negative battery terminal.
The COM and - (negative) ports on the access controller are NOT to be used as earth grounds. Doing so may cause damage to your equipment. Only one end of the drain wire should connect to ground. The other end should not connect to anything.
Please refer to this article to wire your readers.