BECKHOFF EP1908 - Manual (Page 24)

Operation
22 EP1908-0002
Operating mode Description
Two channel encoder
velocity control channel x/y Two-channel evaluation of the frequency. The upper limit frequencies
are specified separately, but should but the same. The same
frequencies have to be supplied, whereby all states are permitted that
may occur at the encoder interface.
The two channels return logical 1 if the current frequency is below the
frequency set under Velocity limit channel x/y.
The minimum supported frequency is 2 Hz. Values below this are
shown as 0. The maximum supported frequency is 500 Hz. Values
above this result in a diagnostic message of the EP1908-0002. This
message can be reset through a rising edge of the safe output signal
ErrAck of the EP1908-0002.
Two channel async. velocity
control channel x/y Two-channel evaluation of the frequencies. In this mode is only the
compliance with the limits for the two channels is monitored. The upper
limit frequencies are specified separately.
The two channels return logical 1 if both frequencies are below the
frequency set under Velocity limit channel x/y.
The minimum supported frequency is 2 Hz. Values below this are
shown as 0. The maximum supported frequency is 500 Hz. Values
above this result in a diagnostic message of the EP1908-0002. This
message can be reset through a rising edge of the safe output signal
ErrAck of the EP1908-0002.
Note
Speed / frequency measurement
The permitted frequency range is between 2 Hz and 500 Hz. Values below are
reported as 0 Hz, values above result in a diagnostic message of the EP1908-0002.
This diagnostic message can be reset through a rising edge at the safe output signal
ErrAck of the EP1908-0002.