Title: Hardware Installation Guide.pdf
Biometric ReadersIt is recommended that the RS-485 transmission line be terminated at both ends. The recommended termination at the PC end of the line is called fail-safe termination.This terminator ensures that there is a proper bias voltage across the receiver inputs. This, in turn, ensures that the receiver is in a known state and puts less of a strain on the driver to provide that bias. This termination is typically built into the RS-232/RS-485 converters and internal PC add-on boards – you should confirm that such a termination exists, but you likely don’t have to supply it yourself.The termination at the opposite end of the transmission line should be parallel (or passive) termination.