Table of Contents
Advertisement
12.1.4 Output Signals
HTL
HTL square-wave signals
The design of encoders with HTL square-wave signals is similar that of encoders with TTL square-wave
signals. Output signals are HTL square-wave pulse trains Ua1 and Ua2 together with the reference pulse
Ua0 that is gated with the incremental signals Ua1 and Ua2.
To each square-wave pulse train the integral electronics in addition outputs the corresponding inverted
signal (not with ERN 1030). The outputs of encoder with HTL square-wave signals are short-circuit proof at
room temperature.
Incremental signals:
Edge separation
The scanning frequency depends on the encoder model and can be seen from the specifications.
Ref. mark signal
Pulse width
Delay time
Fault detection signal
Signal level HTL
Load capacity
Switching times
HTL square-wave pulse trains Ua1 and Ua2 and their inverted
Ua1
pulse trains
and
Ua2 lags Ua1 with ccw rotation (view on shaft or encoder flange).
a ≥ 0.45 µs at 300 kHz scanning frequency
a ≥ 0.8 µs at 160 kHz scanning frequency
1 square-wave pulse Ua0 and its inverted pulse
Ua0
ERN 1030: no
90° elec.
It d l ≤ 50 ns for gated ref. pulse
UaS
1 square-wave pulse
UaS
= LOW: fault detected
UaS
= HIGH: encoder operates properly
(short circuit not permissible after Up)
ERN 1030: no fault detection signal
U H ≥ 21 V with −I H = 20 mA
U L ≤ 2.8 V with I L = 20 mA
if supply voltage is +24 V, without cable
− I H ≤ 200 mA (not true for
≤ 200 mA
I L
C Load ≤ 1000 pF
t + ≤ 200 ns
Rise time:
t − ≤ 200 ns
Fall time:
Ua2
(ERN 1030: no inverted pulse trains).
UaS
UaS
)
- 55 -
Ua0
Advertisement
Table of Contents
