To Next Page

To Previous Page

27 CMVPFB01A

Acyclic Parameter Access

6. Acyclic Parameter Access

6.1 What is Acyclic Data?

Acyclic / non-cyclic / Service access provides a method for the network master to access any drive or

module parameter.

This kind of parameter access is typically used for monitoring or low priority non-scheduled parameter

access.

The SMV PROFIBUS-DP module supports several different methods of doing this.

6.2 Setting the Acyclic Mode

6.2.1 Acyclic Modes

P431 - Acyclic Parameter Access Mode

Default: 0 Range: 0 - 2

Access: RW Type: Integer

P431 is used to select the required Acyclic mode as shown in Table 25. Refer to section 6.3 for details on

type of acyclic mode. The acronym "4WPA" indicates "4 Words Parameter Access".

Table 25: Acyclic Modes

P431 Value Acyclic Mode Description

0 Disabled No acyclic parameter access

1 4WPA-F 4 word parameter access at front

2 4WPA-E 4 word parameter access at end

6.2.2 Acyclic Mode 1

P431 = 1 (Mode 1 - 4WPA-F)

Setting this mode conﬁgures the PROFIBUS-DP module to expect 4 addition cyclic words at the FRONT of

all normal process cyclic data.

6.2.3 Acyclic Mode 2

P431 = 2 (Mode 2 - 4WPA-E)

Setting this mode conﬁgures the PROFIBUS-DP module to expect 4 addition cyclic words at the END of all

normal process cyclic data.

NOTE

Enabling a 4WPA mode adds to the total amount of IN and OUT cyclic data and is reﬂected

in the Channel Data Size parameters P415 and P416. Care should also be taken in selecting

the correct module from the GSD ﬁle when conﬁguring the network master. Changes made

to P431 will only take effect after re-initialising the module.

•

Lenze AC Tech SMVector PROFIBUS-DP User Manual

Questions and Answers: