ProSoft Technology MVI69-EGD User Manual
Page 72
MVI69-EGD ♦ CompactLogix or MicroLogix Platform
Reference
GE Ethernet Global Data Communication Module
Page 72 of 96
ProSoft Technology, Inc.
November 3, 2008
PDU Type = 33
Read Response.
The read response PDU (Read_Resp) is used to return the contents of one or
more contiguous groups of memory from the local node to the requesting
controller. The header defines parameters which apply to the all of the individual
cell references in the message. Each cell reference specifies an offset into the
specified Exchange, the number of bytes of Data, and the Data itself. All data
returned must be padded to the nearest 4 byte boundary.
Packet
Info
Description Data
Source Port:
7937 (0x 1F01)
Destination Port:
7937 (0x 1F01)
Length:
xx bytes (0x 00 XX)
Checksum:
xxxxx (0x XX XX)
EGD's PDU Field:
Offset
Bytes
Hex code
PDU Type:
0
1
0x 20
Message Flag:
1
1
0x HH
Request ID:
2
2
0x HH HH
PVN1:
4
1
0x 01
Option Length:
5
1
0x HH
Message Length:
6
2
0x HH HH
Configuration Signature:
8
2
0x HH HH
Address Type:
10
1
0x HH
Cell count:
11
1
0x HH
Producer ID:
12
4
0x HH HH HH HH
Exchange ID:
16
4
0x HH HH HH HH
Time Stamp:
20
8
0x HH . . . HH
Reserved:
28
4
0x HH HH HH HH
The following four items are referred to as the exchange Cell. Each Cell
contains data from one [EGD Exchange] command line present in the EGD
Module's configuration file.
Offset: reads the DB Register specified in the [EGD Exchange] command.
Length: is Bytes Qty not Words.
Multiple Cells may be returned dependent on the Cell Count: field specified
in the Requesting PDU.
Offset:
32
2
0x HH HH
Length:
34
2
0x HH HH
Data(depends on length
requested):
36
XX
0x HH . . . HH
UDP
EGD:
Padding(to 32 bit
boundary):
XX
XX
0x HH HH