22 Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
return these errors.
Error Code (Hex) Extended Error (Hex) Description of Error
0x04 0x0000 A syntax error was detected decoding the Request Path.
0x05 0x0000 Request Path destination unknown: Probably instance number is not present.
0x06 N/A Insufficient Packet Space: Not enough room in the response buffer for all the data.
0x13 N/A Insufficient Request Data: Data too short for expected parameters.
0x26 N/A The Request Path Size received was shorter or longer than expected.
0xFF 0x2105 General Error: Access beyond end of the object.
See also
Read Tag Service on page 20
The Read Tag Fragmented Service enables client applications to read a tag
with data that does not fit into a single packet (approximately 500 bytes).
The client must issue a series of requests to the controller to retrieve the data
using this service. The client must change the Offset field value with each
request by the number of bytes transferred in the response to the previous
request.
The Byte Offset field is expressed in number of bytes regardless of the data
type being read. In the example following, the data type being read is SINT,
which happens to be a byte. The elements and offset are in the same units,
which is not the case for other data types.
See also
CIP services on page 13
Services Supported by Logix 5000 Controllers on page 18
Reading the tag TotalCount that has 1750 SINTs consists of these four
service requests with service data, as shown in the tables.
1st Message Request Field Bytes (in hex) Description - Symbolic Segment Addressing
Request Service 52 Read Tag Fragmented Service (Request)
Request Path Size 06 Request Path is 6 words (12 bytes) long
Request Path 91 0A 54 6F 74 61 6C 43 6F 75 6E 74 ANSI Ext. Symbolic Segment for TotalCount
Request Data D6 06 Number of elements to read (1750)
00 00 00 00 Start at this byte offset (0) and return as much as will fit
1st Message Reply Field Bytes (in hex) Description - Symbolic Segment Addressing
Reply Service D2 Read Tag Fragmented Service (Reply)
Reserved 00
Read Tag Fragmented Service
Segment Addressing
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