BECKHOFF EP1908 - Manual (Page 34)

Operation
32 EP1908-0002
4.5.3.3 Configuration of the EP1908-0002 for mode Velocity Control Channel x
The TwinSAFE EtherCAT Box also supports direct connection of initiators and encoders for speed
measurement or frequency (24 V
DC
).
If mode Velocity Control Channel x is set, a frequency is determined from two consecutive falling edges of
the respective input signal. This mode can be set for each channel individually.
If the current frequency is below the set limit frequency, the corresponding input channel returns a logical
1. If the frequency is above the set limit frequency, the corresponding channel returns a logical 0.
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.
Parameter:
•
Connect the signals of the sensors used to the respective channel(s).
•
Switch off the sensor test for the inputs used
(Sensor test Channel x active = FALSE)
•
Set the parameter "Logic of Channel x and y" to
"velocity control channel x / single logic channel y" or
"single logic channel x / velocity control channel y" or
"velocity control channel x/y",
depending on which channel(s) of the input pair is to be used for this mode.
•
Set the parameter Velocity limit channel x of the used channel to the required value. The entered
value has the unit 0.1 Hz.
Example for an input signal curve: