A protocol is a data contract
The line between the reader and the panel decides in what form, and with how much context, a card number travels. The product does not change that line; it reads what the line carries. That is why the answer to “which reports can we get” starts at the cable on your gate.
Wiegand: it carries the number, not the state
- The card number and the moment of the pass are read.
- Direction — in or out — is only known when there is a separate reader or a separate line.
- The reader's own fault and tamper state is not visible on the line.
- The line is not encrypted; physical access to the cabinet is a risk.
OSDP: two-way, and it reports state
- Reader state, tamper and fault reports arrive over the same line.
- The line can be encrypted with Secure Channel.
- Because commands can be sent, the reader's display and its audible prompt can be driven.
- Several readers are addressed on one line; the more gates there are, the simpler the wiring gets.
If you do not know your protocol
The panel brand, the model and a photograph of the reader wiring is usually enough; the table on the compatibility page states line by line which item can be measured on which protocol. We do not paint an item green when we cannot measure it: that is what the grey “not measured” badge is for.