YOKOGAWA F3YP14-0N, Руководство пользователя

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4-1
IM 34M6H55-02E 1st Edition : Apr 1, 2002-00
4. Parameters
4.1 Parameters
Of the parameters given Tables 4.2 and 4.3, those listed with two data position numbers
are 2 word data. The smaller data position number contains the low-order word, and the
larger data position number contains the high-order word.
Data position numbers are three-digit numbers; the leading * symbol represents the
value (axis number - 1), ranging from 0 for axis 1 to 7 for axis 8.
Each data position numbers corresponds to a word. Use only READ and WRITE
instructions on a word-basis when accessing from a sequence program. Using
long-word-based instructions may cause unexpected results. You should also use
word-based instructions when accessing from BASIC programs.
z z z z
Fixed-point data
Speed-related data whose unit is [(1/65536) pulses/ms] are fixed point data with 1-word
for the integer part (16 bits) and 1-word for the fractional part (16 bits). Again, the smaller
data position number contains the low-order word, and the larger data position number
contains the high-order word.
Bits for the integer part of the binary data designate the values for 1, 2, 4 ... whilst bits
for the fractional part designate the values for 1/2, 1/4, 1/8, etc. If the integer and the
fractional parts consist of 16 bits each, the least significant bit in the fractional part
represents 1/65536, which means that the data is 32-bit (long-word) with a unit of
1/65536. Negative numbers are expressed as complements of 2, like regular binary
data.
Table 4.1
Bit 31(MSB) 30
O O O
17 16 15 14
O O O
1 0(LSB)
Value Sign bit 16384
O O O
2 1 1/2 1/4
O O O
1/32768 1/65536
High-order word Low-order word
– Example of fixed point data
When setting speed data of 123.45 [pulse/ms] (=123450 [pulses/s]),
123.45 x 65536 = 8090419.2 [(1/65536) pulses/ms]. Thus, we should set 8090419
as long-word data. The high-order word of this data is 123 because
8090419 ÷ 65536 = 123. The low-order word is the remainder, i.e., 29491.
z
z z
z
Sample program for converting speed data
Here, we show a sample sequence program for converting speed data in [pulses/s] into
setting data for the positioning module with unit [(1/65536) pulses/ms].
Let D0001 (long-word data) be the original data ([pulses/s]).
(1) Divide D0001 by 1000 (long-word division) and store the result in D0011. In this
case, since the maximum value of D0001 is 3998000 (3.998 Mpps) and it is
positive, the maximum value of the result is 3998 and the high-order word (D0012)
is always 0. The low-order word of the result of the division (D0011) will become the
high-order word (the integer which is 16 bits long) of the value ([(1/65536)
pulses/ms]) to be set in the positioning module.