Adjustable interference pulse filters

Input filters are used for interference suppression at the encoder and digital inputs. Different filter frequencies can be parameterized according to the application.

The individual inputs are subject to the following filter frequencies:

Inputs

Max. recommended filter frequency

Encoder inputs: track A, track B, track C

RS422 mode: 5 MHz

TTL mode: 1 MHz

Open Collector: 100 kHz

Latch input

1 MHz

Gate/Latch input

1 MHz

Status Input

100 kHz (not adjustable)

Filter function sequence

Index 0x80n1:19 "Filter settings"

Default parameters for 0x80n1:1D "Counter mode"

Setting

Meaning

Setting

Meaning

10dec: 10 kHz

10 kHz filter

 

25dec: 25 kHz

25 kHz filter

 

50dec: 50 kHz

50 kHz filter

 

100dec: 100 kHz

100 kHz filter

0x80n1:1D "Counter mode"

4dec

Encoder open collector

5dec

Counter open collector

250dec: 250 kHz

250 kHz filter

 

500dec: 500 kHz

500 kHz filter

 

1000dec: 1 MHz

1 MHz filter

0x80n1:1D "Counter mode"

2dec

Encoder TTL (single-ended)

3dec

Counter TTL (single-ended)

2500dec: 2.5 MHz

2.5 MHz filter

 

5000dec: 5 MHz

5 MHz filter

0x80n1:1D "Counter mode"

0dec

Encoder RS422 (diff. input)

1dec

Counter RS422 (diff. input)

Index (hex)

Name

Description

0xA0n0:14

Filter violation counter extern latch

Filter frequency overshoot counter for the Latch extern input

0xA0n0:15

Filter violation counter input gate

Filter frequency overshoot counter for the Gate input

0xA0n0:16

Filter violation counter

Filter frequency overshoot counter for the encoder input signals with activated filter

The internal error counters can be reset as follows:

or

0xFB00:01  "Request"

Description

0x9152

Sets the internal error counter for 0xA000:14 "Filter violation counter extern latch"
for channel 1 to zero

0x9153

Sets the internal error counter for 0xA000:15 "Filter violation counter input gate"
for channel 1 to zero

0x9154

Sets the internal error counter for 0xA000:16 "Filter violation counter"
for channel 1 to zero

0x9162

Sets the internal error counter for 0xA010:14 "Filter violation counter extern latch"
for channel 2 to zero

0x9163

Sets the internal error counter for 0xA010:15 "Filter violation counter input gate"
for channel 2 to zero

0x9164

Sets the internal error counter for 0xA010:16 "Filter violation counter"
for channel 2 to zero

Notice

Fast digital inputs – interference from interfering devices

Please note that the input wiring has very little filtering. It has been optimized for fast signal transmission from the input to the evaluation unit. In other words, rapid level changes/pulses in the µs range and/or high-frequency interference signals from devices (e.g. proportional valves, stepper motor or DC motor output stages) arrive at the evaluation unit almost unfiltered/unattenuated. These interferences can be incorrectly detected as a signal.

  • To suppress interference, an additional input filter can be parameterized.
  • Furthermore, EMC-compliant cabling and the use of separate power supply units for the terminal and the devices causing interference are recommended.