We will introduce three new bit instructions and how a logic branch is executed.
We will program a couple of rungs to demonstrate some common bit functions that will be used in the next example program.
These instructions can be found in the “BIT” tab of the instruction selection window.
One-shot
Latch
Unlatch
We will identify each of these new instructions.
We will quickly show other instructions that can be used that are like those instructions we have already used.
Timer/Counter instruction tab:
TON: Timer On-delay
TOF: Timer Off-delay
RTO: Retentive Timer On-delay
RES: Reset
CTU: Count Up counter
CTD: Count Down counter
Compare instruction tab:...
In this control example, a ball mill is used to grind coarse sea salt into very fine salt crystals for use in baking. A salt hopper delivers coarse salt to the ball mill and after a period of 60 seconds in the mill, very fine salt is discharged from the mill to a collection hopper.
Since the moto...
When a PLC programmer starts to develop a program given a software specification, there are several steps that can be taken to ensure a successful implementation.
First, we need to define the “I/O” that will need to be included in the program.
From the specifications, we can see there is a Star...
