Rockwell Automation 160PD1 160 Profibus Communication Module - Manual (Page 42)

6–16 Using the 160-PD1 on Profibus
The Profibus Telegram The Profibus implementation of the 160-PD1 (as specified by the
GSD file) supports 2 different types of independent data transmission.
The 2 words of control and status utilized above is the process data
cyclically transmitted / received, to start / stop the drive, provide a
reference, and get drive feedback. This data transmission provides the
quickest means of communicating with the drive.
An additional parameter data channel is provided which is much
slower, working around the process data channels above, to read/write
parameters to a drive. This handles one parameter at a time, specified
by an index (parameter number) and a data channel.
In the example below, N7:41 contains the parameter number (Index),
and N7:42 contains any data that is to be written to the parameter
specified. These are copied to the Control words of the scanner for
action (N7:32 & 3). The command to read (80h) or write (A0h) is
copied from N7:43 & N7:44 and is shown on Rungs 4 & 5 on the
ladder above, as it forms the MSB part of the Logic Control Word.
This is an example of a read drive parameter (all values in hex)
N7:40 is the Logic Control Word, where LSB = 5F (Drive running),
MSB = 80 (read operation).
N7:41 is the parameter number 2 = [Output Voltage].
N7:50 is the data from the drive on N7:22.
The value of D4h represents 212 Volts decimal.
N7:51 is a copy of the parameter number (Index) in the LSB
and the handshake if read operation was successful (MSB = 1).
This is another example of a read drive parameter
(all values in hex)
N7:40 is the Logic Control Word, where LSB = 5F (Drive running),
MSB = 80 (read operation).
N7:41 is the parameter number 8 = [Heatsink Temperature].
N7:50 is the data from the drive on N7:22.
The value of 45h represents 69 degrees C decimal.
N7:51 is a copy of the parameter number (Index) in the LSB
and the handshake if read operation was successful (MSB = 1).