Datalogic AMT58 Series, Руководство пользователя

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AMT58x-PB Profibus®
38
6.6 DDLM_Data_Exchange
This is the normal operational status of the system. The Slave (no
matter if set to Class 1 or Class 2) can both transmit the
Position
value to the Master and receive the Preset value from the Master.
Position
(Encoder

Master)
Byte 1 2 3 4
Bit 31-24 23-16 15-8 7-0
Data 2
31
to 2
24
2
23
to 2
16
2
15
to 2
8
2
7
to 2
0
This is the position information output by the encoder. The value is
right aligned in the data field.
Preset
(Master

Slave)
Byte 1 2 3 4
Bit 31-24 23-16 15-8 7-0
Data 2
31
to 2
24
2
23
to 2
16
2
15
to 2
8
2
7
to 2
0
The Preset function is meant to assign a desired value to a physical
position of the encoder. The chosen physical position will get the
value set next to this item and all the previous and following positions
will get a value according to it. This function is useful, for example,
when the zero position of the encoder and the zero position of the
axis need to match. The preset value will be set for the position of the
encoder in the moment when the preset value is sent. The
Preset
value is sent by the Master to the Slave in Data_Exchange mode by
setting bit 31 = “1” for 3 cycles.
The MSB of the preset value controls the preset function in the
following way:
Normal operating mode: MSB = 0 (bit 31): the encoder will make no
change in preset value.
Preset mode: MSB = 1 (bit 31): with the MSB = 1 the encoder
accepts the transferred value (bits 0 ... 30) as a preset value in binary
code.
- If
Scaling function = DISABLED, then
Preset must be less than the Hardware total resolution.
- If
Scaling function = ENABLED, then
Preset must be less than the Total resolution