- The Most User-Friendly Ladder Logic Editor,
Compiler and Real-time Ladder Logic Simulator
Click Here for FREE
Downloading of TRiLOGI (Evaluation) Software
Although H-Series PLC may look like an ordinary single-board
computer, they are all programmable using the "Relay-Ladder Logic" language
which is the most popular programming language used by all major manufacturer of PLCs such
as Allan-Bradley, Siemens AG and OMRON, etc. Although programs written in Relay Ladder
Logic cannot directly manipulate the microcontroller's internal hardware as easily as the
assembly language, such programs are however much easier to write and are generally
understood by all electricians around the world who need not have any knowledge about
microcontrollers at all.
Fig 1 - TRiLOGI Editor Screen
Thanks to our extremely powerful yet very user-friendly Relay
ladder logic editor-cum-simulator software - TRiLOGI, programming H-series PLC become an
almost trivial task. TRiLOGI runs on any IBMPC compatible computer and provides complete
pull-down menus, pop-up windows and on-line context-sensitive help systems. As you may
observe from the above screen, you can see that all I/Os may be defined using very
meaningful names such as Start, Stop, etc. in the program and the relationship between
each I/Os are defined by how the imaginary "current" could flow through the
The following sections describe the main features of TRiLOGI
including the types of functions it supports.
1. Insert Element Menu
Fig 2- Intuitive pull-down "Ins Element" Menu
To add an element to the ladder diagram, you simply press the
<Ins> key and pick an item from the Insert Element pull down menu as shown above.
This menu lets you create Normally-Open (NO) or Normally-Closed (NC) contacts in series or
in parallel. One or more coils can be connected by choosing Item "7" or
"8". To insert a special function, select Item "9" or "0"
(for multiple function) and the special function menu will appear as described in the next
2. Special Function Menu
Fig 3 - Special Functions Menu
- Reversible Counter Function: [DNctr], [Upctr] and [Rsctr] -
The [DNctr], [UPctr] and [RSctr] functions work together to implement reversible counter
functions on any of the 128 counters supported by TRiLOGI. Unlike the ordinary
down-counter, a reversible counter is a circular counter which changes the counter present
value (PV) between 0 and the set-value (SV). When you try to increment the counter pass
the "Set Value", it will overflow to become '0'. Likewise if you try to
decrement the counter beyond '0', it will underflow to become the "Set Value".
All three counter functions [DNctr], [UPctr] and [RSctr] can operate on any built-in
- [AVseq],[RSseq] and [StepN] -These 3 functions control any one
of the 8 sequencers supported by TRiLOGI. A sequencer is very useful for programming
machines or processes which operate in fixed sequences. These machines operate in fixed,
clearly distinguishable step-by-step order, starting from an initial step and progressing
to the final step and then restart from the initial step again. [Avseq] advances the step
counter, [Rsseq] clears the counter to inactive and [StepN] function allows you to set the
step counter of the sequencer to any integer value between 0 and 31. [RSctr] - This
function resets the counter to inactive state.
- [Latch],[Clear] - When activated, the associated output or
internal relay will remain ON until it is reset by the [Clear] function acted on the same
output or relay.
[Ilock],[ILoff] - This is equivalent to a master relay with
sub-branches as illustrated below:
Figure 4: [ILock] function & its Equivalence
- [DIFU]-The associated relay will turn on for one scan time
when its execution condition goes from OFF to ON.
- [DIFD]-The associated relay will turn on for one scan time
when its execution condition goes from ON to OFF.
- [MaRST] - An ON condition to this function clears all mailbox
inputs, outputs, relays timers and counter bits to OFF, resets all timers
counters/sequencers to inactive state, and clears all latched relay bits.
3. Special Bits Menu
Fig 5- Special Bits Menu
- Clock Pulse - Six clock pulses with period of 0.01s to 1.0
minute are available on the H-series PLC. They can be used as a NO or NC contact in the
- Normally On Flag - If for some reason you require a
permanently ON or OFF condition this flag can be used to advantage.
- First Scan Pulse - This flag with be turned ON for one scan
time when the PLC is first powered ON or when host computer issue a Reset command.
- Sequencer 1~8 - H-series PLC supports 8 sequencers, and each
step of any one of the sequencer can be used as a contact in the ladder diagram. E.g.
Seq2:5 represents Step #5 of sequencer #2 , which means that the contact with the name
"Seq2:5" will be turned ON when the step counter of the sequencer #2 reaches the
value of '5' and will be OFF when the step counter is at any other value. Each sequencer
supports up to 32 steps (Step #0 to Step #31).
4. Real Time Simulation
Fig 6 - Real Time Simulator Screen
While constructing your ladder program you can simulate it
using TRiLOGI's unique real-time Simulator. When you invoke the Simulator, you will see a
full screen of I/Os organized into 7 columns:
The first two columns show Inputs, followed by Timers,
Counters/Sequencer, Internal Relays and Outputs. Beside each I/O, an indicator lamp
indicates whether the I/O is ON or OFF. You can move the highlight bar to any I/O and
press the <Enter> key to toggle its status and the status of all the other I/Os will
be immediately updated according to the ladder program. A red "*" symbol means
an I/O is ON whereas a grey "." means it is OFF.
5. On-Line Monitoring and Control
TRiLOGI can monitor the status of all the I/Os, Timers and
Counters of the PLC via its RS232C port. It also permits you to pause the PLC and remotely
forced-set or reset any I/Os or even modify the current value of the internal Timers and
Counters. The I/O status can either be monitored on a full screen display similar to the
Simulator-screen, or directly on the ladder diagram. This feature helps greatly during
debugging and fine-tuning of your ladder program.
6. Use of Meaningful Label Names
In TRiLOGI all the I/Os must be defined with unique label
names prior to using them to construct the ladder program. Up to 8 characters of
alpha-numeric names can be defined which means you can create ladder diagram using far
more meaningful names such as "Start" and "Fire" instead of 001, 205
etc. Once defined, the I/O names will be used throughout the entire session of program
creation, simulation and monitoring. Any experienced programmer would be know that a
program with meaningful names is far easier to create, debug and maintain than one made up
of numbers only. Coupled with the powerful Simulator, you have to try it to believe how
easy it is to develop your control program using TRiLOGI !
7. Password to Protect Intellectual
TRiLOGI allows you to set password protection on the target
PLC to prevent unauthorized uploading of your ladder program.
Copyright 2001 Triangle Research International, Inc.
All Rights Reserved