Troubleshooting

GrafcetMaker checks your project while you work. The counters at the top right show the number of errors (red) and warnings (orange); click them to open the Problems list. Click a problem to jump to the element, and use its fix button when there is one. Elements with a problem also carry a badge on the diagram: hover it for the details.

Errors

Grafcet G1 has no initial step. Nothing can ever become active. Select the first step and press the fix Make step … initial, or set its Kind to Initial step.

Several steps have the same number. Numbers must be unique in a grafcet, or Xn would be ambiguous. Use Renumber steps or change a number with F2.

Empty receptivity. Every transition needs a condition. Use 1 for a transition that is always true (the fix does it for you).

Unknown variable. The name is not declared (a file written elsewhere, or a variable deleted). Names you type in a receptivity or an action are created for you; for the others use the fix to create it, or pick the suggested name if it is a typo.

Expression problems (unexpected character, missing parenthesis…). The problem box under the field marks the position and gives a hint. A frequent one: / means NOT before a condition, so write a * /b for "a and not b". See Writing receptivities.

An action assigns an input. Inputs come from the process and cannot be written. Change the variable's direction or use another variable.

Forcing order targets a missing grafcet or step. Check the grafcet name and step numbers in the order.

Warnings

Step … can never become active. No path leads to it from an initial step. Link it, or delete it.

Step … has no outgoing transition. Once active, it stays active for ever. Usually a loop back is missing (L).

The alternative branches are not exclusive. Both receptivities can be true together, which would activate both branches. Make them exclusive, e.g. a and /a * b, or use the fix Give priority to ….

Possible endless transient evolution. A loop of transitions could all be true at once, so the grafcet would never settle. Add a condition, often an edge (↑start), that cannot stay true.

Output set by continuous actions of steps that can be active together. Two parallel branches drive the same output. Drive it from one place, or use stored actions.

An action without a step is stored on deactivation. Without a step the action is always active and never deactivated, so it never runs. Attach it to a step, or change its kind.

Output set by an action without a step and by another action. The output is true whenever any of them is. Make sure that is what you want.

Stored on an event but no event. Enter the event (e.g. ↑b) in the Properties panel.

Expansion needs exactly one entry step and one exit step. In a macro-step expansion, the entry step has no transition above it and the exit step none below it.

Information

Variable … is not used. It is declared but no expression uses it. Delete it with the fix, or keep it for later.

Errors

Warnings

Information

Other questions