Warnings, Acyclic data communication according to dpv1, Overview – Baumer GE-GB-GXxxx User Manual
Page 21: Ds_write
Manual_ProfibusDPV2_BIDE_EN.docx
21/41
Baumer IVO GmbH & Co. KG
22.11.12
Villingen-Schwenningen, Germany
6.8. Warnings
A diagnostic warning is triggered upon the encoder recognizing that specific internal tolerance limits have
been achieved. Conversely to alarms a warning does not consequently mean a position error.
The process sequence of a diagnostic warning is fully identical to that of a diagnosis alarm described in the
above. The difference is made in „Type of Diagnosis“ defining several reasons for warning.
Type of diagnosis:
16 (0x10):
“Frequency exceeded” (threshold signal when exceeding the maximum encoder
speed)
17 (0x11):
„Light Control“ (threshold signal for being at the infrared LED regulating limit)
20 (0x14):
“Battery Voltage Low” (threshold signal for low battery voltage)
6.9. Acyclic data communication according to DPV1
6.9.1. Overview
The parameterization master utilizes acyclic telegrams in line with PROFIBUS-DPV1 to read and if required
to write addressed data in the DP slave by slot, index and parameter number. Prior condition is that the DP
slave is in Data Exchange mode.
Acyclic data communication utilizes system functions DS_Read and DS_Write. DS_Write is appropriate for
writing parameters („Change Parameter“).
A parameter readi
ng operation by DS_Read („Request Parameter“) is always preceded by DS_Write
supplying the slave with all necessary information on the requested parameter read access. Successful exit
of DS_Write may take several bus cycles, afterwards DS_Read can be launched.
6.9.2. DS_Write
SIEMENS controls apply system function SFB53 / WRREC for DS_Write. Parameters to be delivered are
among others index and ID (Slot), “Index=47” as encoder profile parameter, Index=255“ for I&M parameters.
The slot address is the “ID”. For Slot1 it is the programmed E/A address of telegram 81, in the examples
below 512 = 0x200. Slot0 is addressed via the diagnosis address of the DP-Slaves, in the examples below
4093 = 0xFFD.
An additional data block must be prepared for accommodating more parameters. The schematic structure of
this data block is described in the following. Length depending on read/ write access and parameter length
are between 10 and 16 bytes.
DS_WRITE
Called parameter Value
Example
ID
Slot no.1 (E/A address telegram81)
Slot no.0 (diagnisos address slave)
0x0200
0xFFD
Index
47 = 0x2F
255 = 0xFF
0x2F
0xFF
Length
Length of data to be exported out of
the data block (write)
0x0A
Data block (write)
Byte
Significance
Explanation
Example
0
Request Reference
Selectable at will by master, mirrored
in response
0xAA
1
Request ID
Request=1 Change=2
0x01
2
Shaft no.
0= whole slave
0x00
3
Number of parameters
Only one parameter: 1
0x01
4
Attribute
0x10=Value = 0x20=Description
0x30=Text
0x10
5
Number of parameter elements
Several elements (Sub-IDs) during
read/write, counted from Sub-ID
0x04
6
Prm_no hi
High byte of parameter number,
in the example 65000=$FDE8
0xFD
7
Prm_no lo
Low byte of parameter number
0xE8
8
Subindex hi
0x00
9
Subindex lo
0x02
Supplementary bytes
10...15 only with “Change Parameter”: