An object of I/O tag type may acquire values in the system, which are described for individual types in the following tables (only the types, listed below, are described in the tables).
Object value | Cause |
---|---|
D_False | *FALSE value |
D_True | *TRUE value |
D_Oscillate | Oscillating value (TRUE <-> FALSE). The system sets a value as the oscillating one according to defined parameters of filtering - Oscillation limits |
*Valid for the normal polarity. In case of the inverse polarity, then opposite values are valid.
Object value | Cause |
---|---|
D_False | *FALSE value |
D_True | *TRUE value |
D_Oscillate | Oscillating value (TRUE <-> FALSE). The system sets a value as the oscillating one according to defined parameters of filtering - Oscillation limits |
*Valid for the normal polarity. In case of the inverse polarity, then opposite values are valid.
Quaternary inputs are used e.g. in electricity industry. Example of use: opening a pulp valve with logical sensors of the end positions closed and open - can contain the following states:
Object value | Cause |
---|---|
Q_Off | OFF value |
Q_On | ON value |
Q_Trans | TRANS value (ON-OFF change or vice versa) |
Q_Err | ERR value (error state) |
Q_Oscillate | Oscillating value (On <-> Off). The system sets a value as the oscillating one according to defined parameters of filtering - Oscillation limits. |
If no control object and no
default value are defined for an I/O tag, its value will
be invalid after starting the D2000 system.
After restarting process
D2000 KOM, process internally invalidates the values of all I/O tags.
This could be undesirable behaviour (e.g. the values of output I/O tags in server
protocols), therefore starting process D2000 KOM with the parameter
/KI allows to enable loading the initial values of I/O tags (input
as well as output ones) from process
D2000
Server after starting process
D2000
KOM.