A PLC programmer does not need to be a chemical engineer, mechanical engineer, process engineer, electrician, instrumentation specialist, and machine designer all at the same time.
But there is another extreme …
Read MoreA PLC program can work perfectly and still be difficult to troubleshoot.
That distinction matters.
When we first learn ladder logic, the goal is usually simple:
Make the motor run.
Later, the goal becomes …
Read MoreOne of the most useful PLC programming patterns a technician can learn is also one of the simplest:
Trigger → Hold-In → Interrupt
The idea is straightforward.
Something starts the action.
Something keeps it …
Read MoreModern industrial automation systems are no longer isolated PLCs controlling a few inputs and outputs.
Today, a machine may interact with PLCs, HMIs, SCADA platforms, historians, databases, MES systems, remote I/O, …
Read MoreWhen working with Allen-Bradley ControlLogix or CompactLogix systems, one of the first architectural decisions a programmer eventually faces is how to handle physical I/O inside the PLC program.
At the beginning, …
Read MoreIn the first article of this series, we introduced the idea of separating physical PLC I/O from application logic.
Now we can address one of the most common questions in Allen-Bradley …
Read MoreIn the previous article, we built an I/O mapping layer using individual instructions.
For digital signals, we used logic such as:
XIC Physic
al_Input
OTE Internal_Tag
For numeric values, we introduced:
MOV Source Destination
This approach is …
Read MoreIn the previous articles, we built an I/O architecture using:
Direct physical I/O
Alias Tags
Individual mapped tags
XIC/XIO and OTE
MOV
COP
CPS
These methods allow us to separate physical hardware from application logic.
But as the machine …
Read MoreThroughout this series, we have examined several ways to build an I/O architecture in Studio 5000:
Direct I/O
Alias Tags
Individual Mapping
MOV
COP
CPS
UDTs
Each method offers different architectural advantages.
But eventually someone asks:
Which method is fastest?
Or:
Which …
Read MoreThroughout this series, we have explored several different ways to handle I/O in Studio 5000.
We started with the simplest possible approach:
Local:1:I.Data.0
Then we introduced:
Alias Tags
Individual Mapping
MOV
COP
CPS
UDTs
Digital I/O Processing
Analog Scaling
Analog Output Processing
Performance …