Omron DR 170 14 manual Read, Write, Imortant Note

Klinkmann Automation Omron Ethernet DAServer 34

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:		returns ABCDEF
DM10 – DM12C
DM10 – DM11D		returns AC
DM10 – DM12E		returns BDF
Write:
DM10 - DM12C		after written with "ABCD"
DM10	MSB	LSB
	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.

Omron Ethernet DAServer Ver 1.x User Manual Rev 1.3 17014m13