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Values (I/O Tags)

Values (I/O Tags)

Values of I/O tags

An object of the I/O tag type may acquire values, which are described in the following tables for individual types (only the types, listed below, are described in the tables).

I/O tags of Di type - Logical input

Object value

Cause

Object value

Cause

D_False

*FALSE value

D_True

*TRUE value

D_Oscillate

Oscillating value (TRUE <-> FALSE). The system sets a value as oscillating according to defined parameters of filtering - Oscillation limits

*Valid for the normal polarity. In the case of the inverse polarity, then opposite values are valid.

I/O tags of Dout type - Logical output

Object value

Cause

Object value

Cause

D_False

*FALSE value

D_True

*TRUE value

D_Oscillate

Oscillating value (TRUE <-> FALSE). The system sets a value as oscillating according to defined parameters of filtering - Oscillation limits

*Valid for the normal polarity. In the case of the inverse polarity, then opposite values are valid.

I/O tags of Qi type - Quaternary input

Quaternary inputs are used e.g. in power engineering. Example of use: opening a valve with logical sensors of the end positions closed and open - can be in the following states:

  • the value of the sensor open is True, the value of the sensor closed is False, the value of the quaternary input is open - On

  • the value of the sensor open is False, the value of the sensor closed is True, the value of the quaternary input is closed - Off

  • the values of both sensors are False (the pump valve is between end positions), the value of the quaternary input is a transition - Trans

  • the values of both sensors are True (it can be caused by e.g. a communication error or physical sensor damage), the value of the quaternary input is error - Err

Object value

Cause

Object value

Cause

Q_OFF

OFF value

Q_ON

ON value

Q_TRANS

TRANS value (transition from ON to OFF or vice versa is in progress)

Q_ERR

ERR value (error state)

Q_OSCILLATE

Oscillating value (On <-> Off). The system sets a value as oscillating according to defined parameters of filtering - Oscillation limits.

Initial values of I/O tags after starting the D2000 system and after restarting the D2000 KOM process

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 the D2000 KOM process is (re)started, it internally invalidates the values of all I/O tags. This could be undesirable behavior (e.g. the values of output I/O tags in server protocols), therefore starting to process D2000 KOM with the parameter /KI allows enabling reading the initial values of I/O tags (input as well as output ones) from the D2000 Server process after starting the D2000 KOM process.

Related pages:

I/O tags
I/O tag - configuration dialog box