batch mixer interlock (graphical LD)¶


suite id	`g_batch_mixer`
domain	chemical_batch
language	LD-graphical
difficulty	medium
validation status	validated
origin	authored
license	CC-BY-4.0

Authored for this suite to cover this domain with genuine control logic

What is proved¶

From benchmarks/chemical_batch/g_batch_mixer/props.yaml. What each kind claims, and what it becomes on either route, is on The properties we prove.

id	kind	claim	requirement
`P1`	`invariant`	`!(mixer && lid_open)`	The mixer must never run while the lid is open.

Variants¶

file	expected verdict	violates	method
`clean.xml`	SAFE	none	expert
`bomb.xml`	VIOLATION	`P1`	fault-injection

Files¶

file	what it is	size	sha256
`benchmark.yml`	benchmark metadata	0.9 KB	`fd99963e275f`
`bomb.xml`	ladder program, PLCopen XML	3.1 KB	`9728f1a03658`
`clean.xml`	ladder program, PLCopen XML	2.7 KB	`cdd9a6d7a48f`
`props.yaml`	property file	0.2 KB	`f7f0c10bc09f`

Structured text, derived¶

Read off the ladder graph by runner/ld_to_st.py: every rung's contacts and coils rewritten as IEC 61131-3 assignments, in the same series/parallel logic the PLCopen XML encodes. This is a reading aid, not a second source of expected verdicts; ESBMC verifies the ladder program shown above, never this rendering.

bomb.xmlclean.xml

PROGRAM g_batch_mixer_bomb
VAR_INPUT
    mix_cmd : BOOL;
    lid_open : BOOL;
    enable : BOOL;
    maint : BOOL;
END_VAR

VAR_OUTPUT
    mixer : BOOL;
    alarm : BOOL;
END_VAR


mixer := (((NOT lid_open OR (lid_open AND maint)) AND mix_cmd) AND enable);
alarm := lid_open;

END_PROGRAM

PROGRAM g_batch_mixer_clean
VAR_INPUT
    mix_cmd : BOOL;
    lid_open : BOOL;
    enable : BOOL;
    maint : BOOL;
END_VAR

VAR_OUTPUT
    mixer : BOOL;
    alarm : BOOL;
END_VAR


mixer := ((NOT lid_open AND mix_cmd) AND enable);
alarm := lid_open;

END_PROGRAM

Recorded runs¶

A task can carry two routes. ld is ESBMC's ladder front end reading the program directly. via C is the same solver reached through Beremiz and MatIEC, which is the only route that reaches ST, IL, FBD and SFC; see How ESBMC-PLC works.

g_batch_mixer__bomb (props.yaml, expected VIOLATION): v8.4 VIOLATION
g_batch_mixer__bomb__viac via C (props.yaml, expected VIOLATION): master VIOLATION
g_batch_mixer__clean (props.yaml, expected SAFE): v8.4 SAFE
g_batch_mixer__clean__viac via C (props.yaml, expected SAFE): master SAFE