34-bit is the length of the Wiegand number.
If the site already uses another bit length, stay on that format or re-issue cards and reprogram the panel together.
34-bit Wiegand
A 34-bit Wiegand card format. Cards, reader, and panel must share this length.
Also called
34-bit34 bit Wiegand34-bit Wiegandwiegand bits 34 bit
Catalog fields
Wiegand Bits
Source: Transmitter Solutions product training