DDE reference enables to get the status of object value:
= D_2000|ARCH_STATUS!blname_N
D_2000 - DDE Server name (required).
ARCH_STATUS - requirement for status of archive value (archive object).
blname_N is a string consisting of:
- blname - logical name of archive block (COM_ID)
- N – consecutive number of archive value within the archive block
DDE reference returns the string in the format "z1;z2;".
- z1 can be one of these 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 | Dividing by zero. |
- if z1 is "N", DDE reference returns also the second part of the string - z2. This part of the string consists of two characters.
| I_ | In Limit | The value from an 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 example of DDE reference is - here.
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