Pepperl+Fuchs P 58 Series User Manual

Absolute rotary encoder P**58
Encoder classes of the PROFIBUS user organisation
Subject to reasonable modifications due to technical advances. Copyright Pepperl+Fuchs, Printed in Germany
Pepperl+Fuchs Group • Tel.: Germany +49 621 776-0 • USA +1 330 4253555 • Singapore +65 67799091 • Internet http://www.pepperl-fuchs.com
Date of issue 01/15/04
16
4.2.1 Transferring the actual process value
In the case of a Multiturn encoder, the current position value is transferred to the
master as a 32 bit value (double word):
Similarly, transfer for a Singleturn encoder is as a 16 bit value (word).
4.2.2 Preset function
The Preset function can be used to adjust the encoder zero point to the mechanical
zero point of the system. Setting the preset value sets the actual value of the rotary
encoder to the desired "Preset value". The necessary zero point offset is calculated
by the device and stored zero-voltage-safe in an EEPROM (requires less than 40 ms).
The preset value is activated by Bit 31 in the (peripheral) output double word
(accepted with a rising edge). The preset value must be set after the scaling
parameters are transferred, i. e. the preset value refers to the actual scaled value.
(The procedure can be applied to the Singleturn version with appropriate changes –
in this case, Bit 15 is used to activate the preset value.)
If very high precision is required, the preset value should only be set when the rotary
encoder shaft is at rest. If the shaft moves very rapidly during this time, there may be
shifts, since run times may occur through the bus while the preset value is being set.
Word word 1 word 0
Function status bits actual 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
0000000XXXXXXXXXXXXXXXXXXXXXXXXX
Status bits Data bits
Bit
31 30 29 28 2726 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9876543210
Master →
Encoder
1
000000
transfer of desired value (= Preset value)
Encoder
→ Master
0000000
new = desired actual process value is transferred
Master →
Encoder
0000000
reset Bit 31 – normal mode
Encoder
→ Master
0000000
new = desired actual process value is transferred

Pepperl+Fuchs P 58 Series Specifications

General

Brand	Pepperl+Fuchs
Model	P 58 Series
Category	Media Converter
Language	English