Beckhoff KL5101, Documentation, Page: 12 / 40

Product overview
KL5101 12 Version: 3.1
2.3 Basic Function Principles
The KL5101 incremental encoder interface terminal enables the connection of any incremental encoder to
the Bus Coupler or PLC. A 16-bit counter with a quadrature decoder and a 16-bit latch can be read, set or
enabled. In addition to the encoder inputs A, B and C, an additional latch input G1 (24 V) and a gate input
G2 (24 V) for locking the counter are available.
It is also possible for the 16-bit up/down counter operating mode to be selected. In this mode, input B is the
counter input.
1, 2, or 4-fold evaluation of the encoder signals A, B, C in simple or complementary form can be
parameterized via the fieldbus.
The terminal is supplied as a 4-fold quadrature decoder with complementary evaluation of the sensor signals
A, B, C. To operate the encoder interface, the 24 V
DC
operating voltage must be connected to the terminal
contacts in addition to the encoder inputs.
From hardware version 03 (i.e. from 18 June 1998) the KL5101 is delivered with new, additional features:
• If the incremental encoder has an alarm output, it can be connected to the status input of the KL5101.
• A period duration measurement with a resolution of 200 ns can also be carried out.
Operation modes
Can be set via the feature register (default setting incremental encoder):
A, B, zero pulse incremental encoder (default)
Up/down counter with:
• A = count; the positive edges of the input pulses are counted
• B = up/down input
◦ B = 0: Up count direction
◦ B = 1: Down count direction
• C = gate input
◦ C = 0: Counter enabled
◦ C = 1: Counter is locked
Functions
• Counting
• Set counter
• Activate zero pulse and save valid value
• Determination of the period duration between two pulses with a resolution of 200 ns (the time between
two positive edges of input signal A is evaluated).
• Display of a counter overflow or underflow.
Process data
The KL5101 always occupies 6 bytes of input data and 6 bytes of output data. The control/status byte is
located at the lowest byte offset. The data word D0/D1 contains the counter word (read/set), the data word
D3/D4 contains the latch word (read). In period duration measurement mode, the period duration is output in
D2 together with D3/D4.
LED display
The signal LEDs indicate the states of the encoder inputs A, B, C and the status input, as well as the state of
the logic inputs of the gate and the additional external latch. The RUN LED indicates cyclic data exchange
with the higher-level controller. If no process data is exchanged for 100 ms, the RUN LED goes out. The
Power UE LED indicates the operating voltage for the power supply of the incremental encoder.