Introduction
One of the best ways to improve PLC programming skills is to stop thinking only in terms of individual instructions and start thinking in terms of process behavior, equipment states, …
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 previous article, we compared three common ways of representing PLC I/O:
Direct physical I/O
Alias Tags
Mapped controller tags
Now it is time to build the mapping layer itself.
For digital signals, one …
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 MoreIn the previous articles, we explored several ways to organize and transfer PLC data:
Direct I/O
Alias Tags
Individual Mapping
MOV
COP
CPS
UDT-Based Architecture
Now we can bring those concepts together and build a complete digital I/O …
Read MoreIn the previous article, we built a complete digital I/O architecture.
Digital signals are relatively simple:
0 = OFF
1 = ON
Analog signals are different.
An analog input may represent:
Tank level
Pressure
Temperature
Flow
Speed
Weight
pH
Conductivity
Valve position
Motor current
Instead of …
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 …