4: B
ASIC
I
NSTRUCTIONS
4-24
FC6A S
ERIES
MICROS
MART
L
ADDER
P
ROGRAMMING
M
ANUAL
FC9Y-B1726
SFR and SFRN (Forward and Reverse Shift Register)
FC6A Series MICROSmart have a shift register consisting of 256 bits which are allocated to R0 through R255. Any number of
available bits can be selected to form a train of bits which store on or off status. The on/off data of constituent bits is shifted in the
forward direction (forward shift register) or in the reverse direction (reverse shift register) when a pulse input is turned on.
Forward Shift Register (SFR)
When SFR instructions are programmed, two addresses are always required. The SFR instruction is entered, followed by a shift
register number selected from appropriate device addresses. The shift register number corresponds to the first, or head bit. The
number of bits is the second required address after the SFR instruction.
The SFR instruction requires three inputs. The forward shift register circuit must be programmed in the following order: reset
input, pulse input, data input, and the SFR instruction, followed by the first bit and the number of bits.
Reset Input
The reset input will cause the value of each bit of the shift register to return to zero. Initialize pulse special internal relay, M8120,
may be used to initialize the shift register at start-up.
Pulse Input
The pulse input triggers the data to shift. The shift is in the forward direction for a forward shift register and in reverse for a
reverse shift register. A data shift will occur upon the leading edge of a pulse; that is, when the pulse
turns on
. If the pulse has
been on and stays on, no data shift will occur.
Data Input
The data input is the information which is shifted into the first bit when a forward data shift occurs, or into the last bit when a
reverse data shift occurs.
Note:
When power is turned off, the statuses of all shift register bits are normally cleared. It is also possible to maintain the statuses of shift
register bits by using the Function Area Settings as required. See Chapter 5 "Functions and Settings" - "Memory Backup" in the "FC6A Series
MICROSmart User’s Manual".
Note:
The SFR instruction cannot be used in an interrupt program. If used, a user program execution error will result, turning on special internal
relay M8004 and the ERR LED on the FC6A Series MICROSmart. For details about the user program execution errors, see "User Program Execution
Errors" on page 3-10.
Note:
For restrictions on ladder programming of shift register instructions, see "Restriction on Ladder Programming" on page 4-33.
Ladder Diagram
Structural Diagram
I2
I0
R0
Reset
Data
I1
Pulse
R1 R2 R3
Shift Direction
First Bit: R0
# of Bits: 4
I0
I1
SFR
R0
4
I2
Reset
Pulse
Data
First Bit
# of Bits
Structural Diagram
I2
I0
R0
Reset
Data
I1
Pulse
R1 R2 R3
Shift Direction
# of Bits: 4
LOD
LOD
LOD
SFR
I0
I1
I2
R0
4
Instruction
Data
First Bit
# of Bits
R0 to R255
1 to 256
Program List
Summary of Contents for MICROSmart FC6A Series
Page 1: ...B 1726 7 FC6A SERIES Ladder Programming Manual ...
Page 8: ...Preface 7 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 32: ...1 OPERATION BASICS 1 20 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 96: ...3 INSTRUCTIONS REFERENCE 3 18 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 130: ...4 BASIC INSTRUCTIONS 4 34 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 192: ...9 SHIFT ROTATE INSTRUCTIONS 9 12 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 272: ...12 DISPLAY INSTRUCTIONS 12 24 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 284: ...14 REFRESH INSTRUCTIONS 14 6 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 502: ...25 DATA LOG INSTRUCTIONS 25 22 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 546: ...26 SCRIPT 26 44 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...
Page 598: ...APPENDIX A 14 FC6A SERIES MICROSMART LADDER PROGRAMMING MANUAL FC9Y B1726 ...