Omron NT-SERIES - SUPPORT TOOL FOR WINDOWS V4 Operation Manual page 298

Numeral Memory Table
Note
282
Similarly, when 2 words are set, the value –1234567 is treated as
F1234567 in hexadecimal in a numeral memory table entry.
S PT models NT21, NT31, NT31C, NT631, and NT631C
Regardless of the number of allocated words, 2 words are always secured for a
numeral memory table entry and a numeric value is stored as signed binary
data. If the setting for [Storage Type] is decimal, F appearing at the most signifi-
cant digit position is treated as a negative sign. In this case, therefore, the num-
ber of significant digits of a negative value is one digit less than the number of
significant digits of a positive value, as with conventional PT models.
Example: If the settings are BCD and 1 word, the value –123 is treated as F123
in a PC (PLC) word and FFFFFF85 in a numeral memory table entry.
However, the value F123 in a PC (PLC) word is 0000F123 (61731 in
decimal) in a numeral memory table entry if the [Storage Type] is
hexadecimal.
Similarly, if the settings are BCD and 2 words, the value –1234567 is
treated as F1234567 in a PC (PLC) word and FFED2979 in a numer-
al memory table entry. However, the value F1234567 in a PC (PLC)
word is F1234567 (–249346713 in decimal) in a numeral memory
table entry if the [Storage Type] is hexadecimal.
Example
In PC (PLC)
Write To
Word
F123
F1234567
4567
F567
2979
If only one word is allocated although two words are necessary to express a nu-
meric value, only the lower 4 digits of a numeric value are read or written. A suffi-
cient number of words must be allocated for reading/writing a numeric value.
PLC Address
Specify the PC (PLC) address (start address) of the area where numeral memory
table entries are allocated.
I/O Comment
Specify a comment for a PC (PLC) word.
A comment can comprise up to 16 characters.
No. of Words Storage Type
1 word BCD
1 word Binary
2 words BCD
2 words Binary
1 word BCD
1 word Binary
1 word BCD
1 word Binary
Section 7-2
In Numeral Memory Table
FFFFFF85
(in decimal: –123)
FFFFF123
(in decimal: –3805)
FFED2979
(in decimal: –1234567)
F1234567
(in decimal: –249346713)
000011D7
(in decimal: –4567)
00004567
(in decimal: –17767)
FFED2979
(in decimal: –1234567)
FFED2979
(in decimal: –1234567)