Cutler-Hammer D320 PLC, User Manual

Page: 108 / 258

96
D320 PLC User's Manual
Instruction
Mnemonic Shift Register Range
■
Bit
Word
SR Shift Register
Double words
Ladder
1. Condition 1 (Input Data): Condition (1 or 0) of the input data to the starting contact (Sb).
2. Condition 2 (Shift Pulse): Shift clock.
3. Condition 3 (Reset): Reset all the bits from the starting contact (Sb) to the end contact (Eb)
to 0.
Description
1. The SR instruction can be used in the M and K address areas. When the K address area is
used, data is maintained in the event of a power failure.
2. The number of available SR commands is 256. The SR commands can be used independently
of the timer/counter.
3. When the Shift Pulse input (P input) is turned on, the starting contact (Sb) is set to the state of
the Input Data input (I input).
4. As each Shift Pulse occurs, data is shifted by 1 bit from the starting contact (Sb) to the end
contact (Eb). If Sb is at a lower starting bit address than Eb, the data is shifted up from Sb to
Eb. If Sb is at a higher starting bit address than Eb the data is shifted down from Sb to Eb.
5. The total number of bits from Sb to Eb is from a minimum of 2 bits to a maximum of 2,047
bits.
6. Sb and Eb may not be the same bit address (bit size of 1).
7. If the reset input is On, all of the bits from Sb to Eb are set to 0.
SR
condition I SB =
1 EB =
condition P
2
condition R
3
Shift data
(condition 1)
Shift pulse
(condition2)
Reset
(condition 3)
Starting contact no. 0 0 0 1 0
(SB)
(SB+1) 0 0 0 0 1 0
End contact no. 0 0 0 0
(Eb)