BEI Sensors PHU9 Absolute Hollow Shaft Encoder - Manual (Page 14)

PROFIBUS USER MANUAL
14 Preliminary
BEI IDEACOD SAS
Espace Européen de l’Entreprise
9, rue de Copenhague
B.P. 70044 Schiltigheim
F 67013 Strasbourg Cedex
Tél : +33 (0)3 88 20 80 80
Fax : +33 (0)3 88 20 87 87
Mail :
[email protected]
Web : www.bei-ideacod.com
4.2 Data exchange in normal operation
The „DDLM_Data_Exchange mode“ is the
normal operation mode of the device. On
request the encoder transfers the current (position) value to the master. The encoder
can also receive data from the master (e.g.
the preset value in the class 2 configuration).
4.2.1 Transferring the process value
The multiturn encoder transmits the current
position value as a 32-bit-value (double word)
to the master.
Word
Word 1 Word 0
Function Process value
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
The singleturn encoder uses a 16-bit-value
(word) for data transmission.
4.2.2 Preset function
Using the preset function it is possible to adapt
he encoder zero point to the zero point of the
application. When using this function the
current encoder position value is set to the
desired
preset value. The integrated
microcontroller calculates the internal zero
point shift.
The preset value is activated if bit 31 in the
(peripheral) output double word is set to 1
(rising edge). As the preset function is used
after receiving the scaling parameters the
preset value refers to the scaled position
value.