4 Commissioning
4.12 Acyclic data
60
DX-NET-PROFINET2-2
01/22 MN040062EN
www.eaton.com
4.12 Acyclic data
4.12.1 Introduction
Acyclic communications are used to read and write parameters and diag-
nostic data in the variable frequency drive/variable speed starter; they can
take place at the same time as cyclical data is being transferred. This means
that acyclical communications are independent from the selected profile.
In order for acyclic data to be transmitted and diagnostic activities to be per-
formed, the higher-level PLC must feature acyclic services.
4.12.2 Data types
Several data types are defined for using PROFIdrive communication: PROFI-
drive-specific data types as well as standard data types.
PROFIdrive-specific data types
TimeDifference
The value used for TimeDifference is stored in the “Sampling Time”
(PNU 962) parameter.
Table 36:
TimeDifference
Example:
100 ms
≙
4971
dec
≙
136B
hex
86400000 ms (= 1 day)
≙
4294967295
dec
≙
FFFFFFFF
hex
Normalized value N2
N2 is a normalized 16-bit value for relative scaling.
N2 falls within a range of -200% to +200%.
￫
This section is intended for programming experts.
￫
In order for acyclic data to be transmitted and diagnostic activi-
ties to be performed, the higher-level PLC must feature acyclic
services.
Data type
Code
[dec]
Code
[hex]
Bytes
Value range
Resolution
TimeDifference
13
D
2
0
≦
i
≦
4294967295
2
-31
≙
0.021 ms
