TMC424 Datasheet – (V1.04 / 2015-JUL-01)

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Copyright © 2011 TRINAMIC Motion Control GmbH & Co. KG

7 Configuration Datagrams

7.1 Encoder Interface Prescaler and Null Event Configuration

The Encoder Interface Initialization datagram configures the parameterizeable encoder prescaler to

adapt the TMC424 for different incremental encoders. Furthermore the TMC424 behavior concerning the

N channel can be selected.

Example: A 1000 steps per rotation encoder is to connect at a stepper motor with 12800 microsteps per rotation. When the

next event at the high active N channel is found, the position register must set to zero. Only Encoder Interface 1 is connected.

The following datagram performs this task:







Bit

Encoder Interface Initialization

31…28

“0000” Register Address

27…25

Interface Selection

000 = Interface 1

001 = Interface 2

010 = Interface 3

011 = Interface 1, 2 and 3

24

‘1’

23…12

External Encoder Resolution and Corresponding Prescaler Factor

Bits 15 … 12:

Fractional part of Factor. Unit: 1/16 (when bit 23 = 0) resp. 1/5 (bit 23 = 1)

Bits 22 … 16:

Integer part of Factor

Bit 23:

Switches Fractional part between 1/5 resolution or 1/16 resolution

Default:

(010)

(default value after power on)

Example settings:

Encoder: 1024 lines (4096 steps per rotation)

Encoder: 1000 lines

Encoder: 512 lines

Encoder: 500 lines

Encoder: 256 lines

Encoder: 250 lines

Encoder: 200 lines