two-hand control as a function block¶


suite id	`g_two_hand_fb`
domain	manufacturing
language	LD-graphical
difficulty	medium
validation status	candidate
origin	authored
license	CC-BY-4.0
syntax pair of	`g_two_hand`

The ISO 13851 Type II logic of g_two_hand moved into a reusable function block, the shape certified safety libraries ship it in

What is proved¶

From benchmarks/manufacturing/g_two_hand_fb/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`	`!Stroke \|\| (LH && RH)`	ISO 13851 requires the ram to descend only while both actuators are held. Releasing either one stops the stroke.

Variants¶

file	expected verdict	violates	method
`program.xml`	SAFE	none	expert
`type_i.xml`	SAFE	none	fault-injection

Files¶

file	what it is	size	sha256
`benchmark.yml`	benchmark metadata	1.4 KB	`df2981b0eff8`
`program.xml`	ladder program, PLCopen XML	3.7 KB	`d2d99912ea21`
`props.yaml`	property file	0.2 KB	`01c905820f28`
`tiedown_check.props.yaml`	property file	0.5 KB	`d1118ab8f733`
`type_i.xml`	ladder program, PLCopen XML	3.6 KB	`fda94b735538`

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.

program.xmltype_i.xml

PROGRAM g_two_hand_fb
VAR_INPUT
    LH : BOOL;
    RH : BOOL;
END_VAR

VAR_OUTPUT
    Stroke : BOOL;
END_VAR

VAR
    THC0 : TwoHandII;
END_VAR


THC0(EN:=TRUE, LH:=LH, RH:=RH);
Stroke := THC0.Stroke;

END_PROGRAM

PROGRAM g_two_hand_fb_type_i
VAR_INPUT
    LH : BOOL;
    RH : BOOL;
END_VAR

VAR_OUTPUT
    Stroke : BOOL;
END_VAR

VAR
    THC0 : TwoHandII;
END_VAR


THC0(EN:=TRUE, LH:=LH, RH:=RH);
Stroke := THC0.Stroke;

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_two_hand_fb__program (props.yaml, expected SAFE): v8.4 SAFE — ingestion gate failed on v8.4
g_two_hand_fb__type_i (props.yaml, expected SAFE): v8.4 VIOLATION
twohand_fb_tiedown_i (tiedown_check.props.yaml, expected SAFE): master VIOLATION
twohand_fb_tiedown_ii (tiedown_check.props.yaml, expected VIOLATION): master VIOLATION — ingestion gate failed on master