Omron DR 170 14 User Manual
Page 36
Klinkmann Automation Omron Ethernet DAServer
34
Omron Ethernet DAServer Ver 1.x User Manual Rev 1.3 17014m13
High-order Byte
Only the high-order byte (MSB - most significant 8-bits) of each
word is used for read. To use this format, append the suffix 'D'
to the item name.
Both Bytes
Both bytes of each word are used for read/write. To use this
format, append the suffix 'C' to the item name.
Note: All bytes in the specified memory range will be used. If the string is shorter
than the range of memory specified, it will be padded with '\0'. If the string is longer
than the range of memory specified, the string will be truncated.
For example, assume the following memory contents (numeric values shown in
hex):
MSB
LSB
DM10
41
42
"AB"
DM11
43
44
"CD"
DM12
45
46
"EF"
Read:
DM10 – DM12C
returns ABCDEF
DM10 – DM11D
returns AC
DM10 – DM12E
returns BDF
Write:
DM10 - DM12C
after written with "ABCD"
MSB
LSB
DM10
54
65
"AB"
DM11
73
74
"CD"
DM12
0
0
" "
DM10 - DM12E
after written with "ABCDE"
MSB
LSB
DM10
0
41
"A"
DM11
0
42
"B"
DM12
0
43
"C"
Imortant Note!
Do not operate with item names, which have addresses outside really existing PLC
data and memory area! It will lead to communication failures, because the DAServer
recognizes item name error only if item name goes out of range represented in the item
names table. Usually the information like following will be logged to logger if some item
with address in inaccessible memory area is used (MRC:11 and SRC:03 informs about
"Parameter error: the first address is in an inaccessible area")
error: the first address is in inaccessible area.