Requirement for value status
Requirement for status of object value
DDE reference that enables to get the status of object value:
= D_2000|STATUS!objname
D_2000 - DDE Server name (required).
STATUS - requirement for status of object.
objname - object name.
DDE reference returns a string in the format "z1;z2;".
z1 can be one of the characters: N, U, O, D or E.
N
Normal
Valid value.
U
Undefined
Undefined value.
O
Out of Range
Value out of range.
D
Error
Error.
E
Div by Zero
Divide by zero.
if z1 is "N", DDE reference returns also the second part of string - z2. This part of the string consists of two characters.
I_
In Limit
The value from the interval <LL..HL>.
VL
Very Low Limit
The value is lower than VLL.
L_
Low Limit
The value is lower than LL.
H_
High Limit
The value is higher than HL.
VH
Very High Limit
The value is higher than VHL.
T_
Transient
Transient status - there was executed a command to set the object value, but there has not been verified the setting of value by backward reading yet.
D_
Default
Default value.
W_
Weak
Weak value - the system does not consider this value as valid because there have not been fulfilled all the conditions of its validity.
WC
Weak Cmd
Weak Command.
WA
Weak Ans
Weak Answer.
LP
Limits Problem
Crossing of the dynamic limits - the condition VLL<LL<HL<VHL has been broken.
The string that returns DDE reference D2000|STATUS!objname can be converted into:
label of the value status - by the function GetValueStatusStr,
label of the value limit - by the function GetValueLimitStr.
The example of DDE reference is - here.