Chapter 5 Instruction Specifications
5-93
Item number Application instructions-21 Name Encode
Ladder format Condition code Processing time (µs) Remark
R7F4 R7F3 R7F2 R7F1 R7F0 Average Maximum
ENCO (d, s, n) DER ERR SD V C
↕zzz ↕
Instruction format Number of steps
Condition Steps
As per the table
below.
ENCO (d, s, n) 4
Bit Word Double word
Usable I/O XY
R,
M
TD, SS,
CU, CT WX WY
WR,
WM TC DX DY
DR,
DM
Constant
Other
dDecode destination head I/O {{
s Word I/O to be encoded {
nNumber of bits to be
encoded {1 to 8 (decimal)
Function
•Encodes the bit location 2n in the range between s and s + 2n – 1 where the bit is “1,” and outputs the result to d (n = 1 to 8).
Upper bits (16-n) of d are set to “0.”
•If n is “0,” the instruction will not be executed and the contents of d retain the original values.
•If there are more than one bits that are set to “1” between s and s + 2n – 1, the upper bit location will be encoded.
•If all the bits from s to s + 2n – 1 are '0', '0' is output to d, and C (R7F0) is equal to '1.' In other cases, C (R7F0) is set to '0.'
b15 b7 b0s+2n-1 s+B
1
s
2n
000 0BH
d
n bits (1 to 8)
Notes
•Use this instruction so that s + 2n− 1 does not exceed the I/O range (R7BF and M3FFF). If it exceeds the I/O range, DER is
set to '1' and the encoding is performed at the maximum range starting from s.
•Use 1 to 8 for n.
Program example
X00001
LD X00001
AND DIF1
[
ENCO (WR0000, R000, 4)
]
ENCO (WR0000, R000, 4)
DIF1
Program description
•Upon the leading of X00001, the most significant bit that is set to “1” is detected within the row of bits R000 to R00F (24 –1
= 15 bits), and a four-bit binary number is set in the word I/O of d.
Example) If “1” is set in the 7th and 6th bits of R000 to R00F, H0007 is set in WR0000.
ENCO (d, s, n)
Processing time (µs)
nAverage Maximum
1 128 –
2 128 –
3 128 –
4 187 –
5 126 –
6 126 –
7 126 –
8 126 –