Reader beeper needs to be disabled so the reader makes no noise during operation including when a card is being badged at the reader.
EcoStruxure Security Expert
Security Expert Smart card readers
When attempting to disable reader beeper by toggling the Disable buzzer processing option under Reader expanders Reader options tab the reader will beep when a card is read.
Disable buzzer processing: When this option is enabled the reader expander will not control the reader beeper. The reader will beep once when a card is read, but will not beep additional times to indicate access granted or denied. The BZ output can be used for another function.
Unfortunately the reader beeper cannot be completely disabled, it will continue to produce a single beep when a card is read. This single beep on card reads is hardcoded into the reader firmware.