Omron ETHERNET DIRECT DR 170 14 - Manual (Page 39)

Klinkmann Automation Omron Ethernet DAServer 37
Omron Ethernet DAServer Ver 1.x User Manual Rev 1.4 17014m14
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")
<Socket.Controller>: FINS command 0101 failed (resp. error code 1103). Parameter
error: the first address is in inaccessible area.