Siemens SINAMICS G110D, Operating Instructions Manual

Page: 180 / 224

Functions
6.11 Operation in fieldbus systems
SINAMICS G110D
180
Operating Instructions, 07/2016, FW V3.63, A5E36768472B AB
Serial data transfer
The CTT2 protocol allows both cyclic and acyclic serial data to be transferred between
master and slave. The commands implemented to achieve this are as shown in the table
below.
Table 6- 66 CCT2 commands
Code (dec) Code (hex) Command/Response Followed by
0 0x00 Read cyclic data from slave 4 byte PWE data
1 0x01 Write cyclic data to slave 4 byte PWE data
16 0x10 Standard read request Index, length
80 0x50 Standard read response ok Data
144 0x90 Standard read response error Standard error code
17 0x11 Standard write request index, length, data
81 0x51 Standard write response ok
145 0x91 Standard write response error Standard error code
18 0x12 Vendor specific read request index, length
82 0x52 Vendor specific read response ok data
146 0x92 Vendor specific read response error error object
19 0x13 Vendor specific write request Index, length, data
83 0x53 Vendor specific write response ok
147 0x93 Vendor specific write response error error object
29 0x1D Vendor specific exchange request index, read length, write
length, write data
93 0x5D Vendor specific exchange response ok read data
157 0x9D Vendor specific exchange response error error object
CTT2 Error Codes
In the event that an acyclic request cannot be successfully responded to the following
standard error codes are used.
Table 6- 67 Standard error codes
Error code Description
0 no error
1 Illegal index
2 Illegal length
3 request not implemented
4 busy (request was not executed completely within time frame; try again later)
5 last acyclic request not acknowledged
6 Illegal sub index
7 Command "selective read request" is missing
Vendor specific response errors contain an error object. This consists of the appropriate
standard error code followed by up to four bytes of optional further data. Inverters will not
use the optional extra data and so will transmit an error object of only one byte in length.