用SCL可以达到你的目的：
FUNCTION_BLOCK FB510{S7_m_c:='true',S7_blockview:='big'}

VAR_INPUT
IN1{S7_m_c:='true'}:bool;
PT{S7_m_c:='true'}:DINT:=120;
END_VAR
VAR_OUTPUT
OUT1{S7_m_c:='true'}:bool;
end_var
var
INPre:bool;
cout1:dint;
OutEn:bool:=true;
end_var;
begin
if INPre<>IN AND IN and OutEn then
OUT:=1;
OutEn:=0;
end_if;
INPre:=IN;
if OUT THEN
OUT:=FALSE;
END_IF;
if NOT OutEn then
cout:=cout+1;
if cout cout>PT*10*60 THEN
cout:=0;

OutEn:=true;
end_if;
end_if;
end_function_block