Overview and Quick Start

What B9X Ladder Editor is

B9X Ladder Editor is a graphical control-programming environment based on relay ladder logic. A program is built from horizontal rungs. Contacts and comparison elements form a condition on the left; coils, timers, counters, assignments, calls, and other actions appear toward the right. The completed project can be saved, reopened, reviewed, and exported as B9X Basic or Arduino source.

How to use this reference

Begin with the quick-start workflow, then use the element reference while building rungs. The operators and expressions chapter explains how series and parallel paths combine. The design and troubleshooting chapters cover reliable program structure. Examples are intentionally small so each rule is visible.

Language scope

The ladder language is graphical. Terms such as operator, statement, clause, and expression describe the behavior of rungs and elements; users do not type a separate textual ladder syntax. Function calls and include elements connect ladder conditions to customer-supplied B9X Basic or Arduino routines.

Create a project

Add a rung, place the required contacts from left to right, add an output or action, select each element, enter its Label, GPIO, Value, and Debounce settings as applicable, and choose Apply. Add a clear rung comment. Repeat for each operation.

Test the logic on paper

Read every rung from left to right and the project from top to bottom. Verify what happens when every input is 0, when each input changes, when timers finish, and when resets occur. Confirm that mutually exclusive outputs cannot be true together.

Save and export

Use Save App to preserve the editable ladder project. Use Load App to reopen it. Export B9X Basic .bas for B9X Basic or Export Arduino .ino for Arduino. A compressed Arduino option is available when a compact sketch is preferred. The configured rung limit is checked before export.

Ladder Language Fundamentals

Program scan

A ladder program is evaluated repeatedly from the first rung to the last. Within each rung, contact groups form the condition and actions operate from that condition. Rung order therefore affects behavior.

Rung anatomy

• Contacts and comparisons form the condition.
• Series groups produce AND logic.
• Parallel branch contacts produce OR logic.
• Coils and control blocks perform actions.
• A rung comment records intent and assumptions.

Fields and Data Types

Element fields

Data types

Naming rules

• Begin names with a letter and use descriptive letters, digits, and underscores.
• Use the same spelling and capitalization for every reference.
• Use a trailing dollar sign for B9X Basic strings, such as message$.
• Leave GPIO blank for internal states and non-I/O elements.

Operators, Statements, Clauses, and Expressions

Statements

A statement is an action controlled by a rung expression: a coil, timer, counter, reset, sequencer, assignment, print, call, or include action.

Clauses

A rung is equivalent to a conditional clause: when the combined contact expression is true, perform the action. Inverse behavior is formed with NC contacts or complementary comparisons.

Expressions

• Boolean series/parallel expressions
• Numeric comparisons
• Rising and falling edge expressions
• Timer/counter/sequencer done expressions
• Coil and internal-state expressions

Complete Element Reference

Each example appears before the resulting value or state.

Contacts

Branches

Outputs

Timers

Counters

Analog and temperature

Comparisons

Control

Functions and inclusion

Data and diagnostics

Editor and Project Commands

Export Reference

B9X Basic

Export B9X Basic .bas creates a B9X Basic program. String names use a trailing dollar sign. PRINT accepts quoted text or a string variable; PRINT DBL prints a numeric variable.

Arduino

Export Arduino .ino creates a readable sketch. Export Compressed Arduino .ino creates a compact sketch. Include content must be valid for the selected target.

Rung limit

Export is cancelled if the project exceeds the configured rung limit.

Programming Patterns and Examples

Start/stop seal-in motor

1. Rung 1: Branch NO startButton and B Coil NO motorRelay in the same parallel group; place the StopHealthy condition in series; finish with OUT motorRelay.
2. Operation: pressing Start turns on motorRelay. Its state contact holds the path after Start is released. Removing StopHealthy breaks the series path and turns the motor off.
3. Review: confirm the actual stop circuit produces the intended logical level and use suitable hardware for safety functions.

Five-second delayed output

1. Rung 1: NO enableSwitch followed by TON readyDelay, Value 5000.
2. Rung 2: T DN NO readyDelay followed by OUT readyLamp.
3. Operation: readyLamp turns on after enableSwitch remains true for five seconds and turns off when normal TON timing is cleared.

Ten-part batch counter

1. Rung 1: ↑ partSensor followed by CTU partCount, Value 10.
2. Rung 2: C DN NO partCount followed by SET batchComplete.
3. Rung 3: NO resetButton followed by C RST partCount.
4. Rung 4: NO resetButton followed by RST batchComplete.
5. Operation: each accepted part edge counts once. The completion state latches at ten and the reset button clears both counter and latch.

Temperature-controlled heater with hysteresis

1. Rung 1: TEMP roomTemperature; use < roomTemperature with Value 68 followed by SET heaterDemand.
2. Rung 2: > roomTemperature with Value 72 followed by RST heaterDemand.
3. Rung 3: Coil NO heaterDemand followed by OUT heaterRelay.
4. Operation: the heater turns on below 68 and stays on until temperature rises above 72. The four-degree separation prevents rapid switching near one threshold.

Mutually exclusive outputs

1. Use separate step/state conditions for each OUT coil.
2. Add Coil NC contacts for every conflicting output when an additional interlock is needed.
3. Verify each possible state, including startup and reset, and confirm that no two output conditions can be true during the same scan.

Design Rules and Safety

• Write a clear comment for every rung.
• Use GPIO only for actual physical I/O.
• Use edges or ONE SHOT for actions that must occur once.
• Avoid duplicate OUT writers.
• Give every SET state a reset path.
• Use hysteresis for analog switching.
• Define startup and reset behavior.
• Review rung order and mutually exclusive outputs.
• Use appropriate electrical drivers and protection.
• Do not use ordinary software logic as the only personnel-safety system.

Troubleshooting

Glossary