Allen-Bradley SLC 500 Series User Manual

Publication 1747-RM001G-EN-P - November 2008
7-10 Application Specific Instructions
Use SQC
When the status of all non-masked bits in the source word match those of the
corresponding reference word, the instruction sets the found bit (FD) in the
control word. Otherwise, the found bit (FD) is cleared.
The bits mask data when reset and pass data when set. The instruction will not
change the value in the destination word unless you set the mask bits. The
mask can be fixed or variable. If you enter a hexadecimal code, it is fixed. If
you enter an element address or a file address for changing the mask with each
step, it is variable.
When the rung goes from false-to-true, the instruction increments to the next
step (word) in the sequencer file. Data stored there is transferred through a
mask and compared against the source data for equality. If the source data
equals the reference data, the FD bit is set in the SQC’s control counter.
Current data is compared against the source every scan that the rung evaluates
as true.

Allen-Bradley SLC 500 Series Specifications

General

Programming Software	RSLogix 500
Series	SLC 500
Category	Controller
Manufacturer	Allen-Bradley (Rockwell Automation)
I/O Capacity	Up to 4096 I/O points
Communication Ports	DH-485
Programming Languages	Ladder Logic
Operating Temperature	0 to 60 °C (32 to 140 °F)
Relative Humidity	5% to 95% (non-condensing)
Memory	4K to 64K words (depending on the processor)
Power Supply	AC or DC (depending on the module)