Pcv Parameter Access - Danfoss VLT Profinet MCA 120 Operating Instructions Manual

How to Control the Frequenc... Operating Instructions

6.2 PCV Parameter Access

Parameter access via the PCV channel is performed by the PROFINET cyclical data exchange, where the PCV channel is part
of the PPOs described in chapter 6 How to Control the Frequency Converter.
Using the PCV channel it is possible to read and write parameter values, as well as readout of a number of describing
attributes of each parameter.
6.2.1 PCA Handling
The PCA part of PPO types 1, 2 and 5 can handle several tasks. The master can control and supervise parameters and
request a response from the slave, whereas the slave can respond to a request from the master. Requests and responses is a
handshake procedure and cannot be batched, meaning that if the master sends out a read/write request, it has to wait for
the response, before it sends a new request. The request or response data value will be limited to maximum 4 bytes, which
implies that text strings are not transferable. For further information, see chapter 9 Application Examples.
6 6
6.2.2 PCA - Parameter Characteristics
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
RC SMP PNU
Table 6.2 PCA - Parameter Characteristics
RC: Request/response characteristics (Range 0..15)
SMP: Spontaneous Message (Not supported)
PNU : Parameter no. (Range 1..1999)
26 Danfoss A/S © Rev. 2014-02-27 All rights reserved. MG90U302