Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 427

Shift Instructions
Precautions
Flags
7-16-9 REVERSIBLE SHIFT REGISTER – SFTR(84)
Limitations
Description
Flags
If a power failure occurs during a shift operation across more than 50 words, the
shift operation might not be completed.
A 0 will be shifted into the most significant digit of St every cycle if the undifferen-
tiated form of SRD(75) is used. Use the differentiated form (@SRD(75)) or com-
bine SRD(75) with DIFU(13) or DIFD(14) to shift just one time.
ER: The St and E words are in different areas, or St is less than E.
Indirectly addressed DM word is non-existent. (Content of *DM word is
not BCD, or the DM area boundary has been exceeded.)
Ladder Symbols
SFTR(84) @SFTR(84)
C
St
E
St and E must be in the same data area and St must be less than or equal
to E.
DM 6144 to DM 6655 cannot be used for C, St, or E.
SFTR(84) is used to create a single- or multiple-word shift register that can shift
data to either the right or the left. To create a single-word register, designate the
same word for St and E. The control word provides the shift direction, the status
to be put into the register, the shift pulse, and the reset input. The control word is
allocated as follows:
15 14 13 12
The data in the shift register will be shifted one bit in the direction indicated by bit
12, shifting one bit out to CY and the status of bit 13 into the other end whenever
SFTR(84) is executed with an ON execution condition as long as the reset bit is
OFF and as long as bit 14 is ON. If SFTR(84) is executed with an OFF execution
condition or if SFTR(84) is executed with bit 14 OFF, the shift register will remain
unchanged. If SFTR(84) is executed with an ON execution condition and the re-
set bit (bit 15) is OFF, the entire shift register and CY will be set to zero.
ER: St and E are not in the same data area or ST is greater than E.
Indirectly addressed DM word is non-existent. (Content of *DM word is
not BCD, or the DM area boundary has been exceeded.)
Operand Data Areas
IR, SR, AR, DM, HR, LR
C
IR, SR, AR, DM, HR, LR
St
E
IR, SR, AR, DM, HR, LR
Not used.
Shift direction
1 (ON):
0 (OFF): Right (MSB to LSB)
Status to input into register
Shift pulse bit
Reset
Section 7-16
C: Control word
St: Starting word
E: End word
Left (LSB to MSB)
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