Westermo RM-505U-K - Manual (Page 39)

man_505U-K_1.4.doc Dec 2008
    ELPRO Technologies Pty Ltd 2008 Page 39
4.7.2 Shaft Encoder Inputs
If the pulse inputs are connected to a shaft encoder (incremental or quadrature types), then the
Shaft Encoder Inputs option should be selected. The 505K will then look at both pulse input
signals and calculate a “position” value for the shaft encoder.
If an incremental encoder is used, then the correct counter value will be stored in the PI1
counter. If a quadrature encoder is used, the value will be stored in the PI2 counter. Note
that you don’t need to select which type of encoder is used. The 505K will calculate both
values. Only the base counters should be used; do not use the Hi or overflow counters.
If the pulse rate from the encoder is greater than 10Hz, then Fast Pulse Inputs should be
selected as for normal pulse inputs. The scaling divider for PI2 must be set to 1.
To physically set up the shaft encoder, set the shaft encoder to the middle of the range, then
manually set the counter value to the value required (refer section 5.3.2). As the encoder
moves up and down, the counter value will increase or decrease.
4.7.3 Pulse Rates
The 505K
calculates the
rate of the pulse
inputs and makes
these values
available to be
mapped as
internal analogue
inputs. For PI2,
the pulse rate is
calculated on the
scaled counter -
that is, after the
input is divided.
The maximum
rate that can be
calculated for both inputs
is 1000Hz.
The maximum value of
the pulse rate is user-
configurable. That is,
you select the maximum
rate that corresponds to
100% of the analogue
value. For example, if
the normal pulse rate is 35Hz, you may decide that the maximum signal should be 50Hz.
The 505K will then transmit 100% value at 50Hz. The maximum pulse rate can be
configured from 0.02 Hz to 1000Hz.
For shaft encoder inputs, you can use PR1 for incremental encoders and PR2 for quadrature
encoders. The rate signal will be 50% for 0 Hz, between 50 – 100% when the encoder is
increasing and 0 – 50% when the encoder is decreasing. If you configure the maximum pulse