In the previous post, we covered the basic PLC timer instructions:
TON = Timer On Delay
TOF = Timer Off Delay
RTO = Retentive Timer On
Now we are going one step deeper.
In real …
Read MoreIn industrial automation, PLC counters are used when a machine needs to count events.
A counter can count:
Parts
Boxes
Bottles
Cycles
Machine strokes
Rejects
Pallets
Sensor pulses
Production totals
A counter does not count time.A counter counts how many times …
Read MoreIn the previous post, we covered standard PLC counters such as:
CTU = Count Up
CTD = Count Down
CTUD = Count Up / Count Down
Those counters work well for many basic counting …
Read MoreIn PLC programming, not every instruction directly turns on a motor, counts a box, or starts a timer.
Some instructions are used to control how the PLC program executes.
These are called …
Read MoreIn PLC troubleshooting, one of the most powerful and dangerous tools is forcing.
A PLC force allows a technician or programmer to manually override the normal state of an input or …
Read MoreIn PLC programming, not all logic is simple ON/OFF control.
Sometimes the PLC needs to work with numbers.
The PLC may need to:
Move a value from one tag to another
Compare a process …
In PLC programming, not all logic is simple ON/OFF control.
Sometimes the PLC needs to work with numbers.
The PLC may need to:
Move a value from one tag to another
Compare a process …
In many PLC programs, the machine does not only turn devices ON and OFF randomly.
The machine often needs to follow a specific order.
For example:
Step 1: Start conveyor
Step 2: Detect product
Step …
A PLC program can be well written, but if the PLC system is poorly installed, the machine can still have problems.
Many PLC issues are not caused by bad ladder logic.
They …
Read MoreIn industrial automation, a PLC panel can have a perfect program and still behave incorrectly if the electrical installation has noise or grounding problems.
Electrical noise can cause problems such as:
Random …
Read More