3
3-8
TCP/IP Ethernet Communications User’s Manual - August 1997 GFK-1084B
COMMREQ Status Word: The Ethernet Interface updates the CRS word to show success
or failure of the command. Command words 3 and 4 specify the PLC memory location
of the CRS word.
(Word 3) COMMREQ Status Word Pointer Memory Type: This word specifies the memory
type for the CRS word. The memory types are listed in the table below.
Type Value
(Decimal)
Value
(Hex.)
Description
%R 8 08h Register memory (word mode)
%AI 10 0Ah Analog input memory (word mode)
%AQ 12 0Ch Analog output memory (word mode)
%I 16
70
10h
46h
Discrete input memory (byte mode)
Discrete input memory (bit mode)
%Q 18
72
12h
48h
Discrete output memory (byte mode)
Discrete output memory (bit mode)
%T 20
74
14h
4Ah
Discrete temporary memory (byte mode)
Discrete temporary memory (bit mode)
%M 22
76
16h
4Ch
Discrete momentary internal memory (byte mode)
Discrete momentary internal memory (bit mode)
%G 56
86
38h
56h
Discrete global data table (byte mode)
Discrete global data table (bit mode)
(Word 4) COMMREQ Status Word Pointer Offset: This word contains the offset within
the memory type selected. The status word pointer offset is a zero-based number. For ex-
ample, if you want %R1 as the location of the CRS word, you must specify a zero for the
offset. The offset for %R100 would be 99. Note, however, that this is the only zero-
based field in the Channel commands.
For information on the contents of the COMMREQ Status word, see Section 4.
(Word 5): Reserved. Set to zero.
(Word 6): Reserved. Set to zero.
(Words 7 and up) Data Block: The Data Block defines the Channel command to be per-
formed. For information on how to fill in the Channel command information, see Sec-
tion 3.