Digital Status Tag Type Properties: I/O Tab
The I/O Tab holds the properties used to identify and establish a connection to the communication driver tag being used to exchange data with your physical I/O device (e.g. PLC or RTU), or to the polling driver responsible for determining the order and rate at which data polls will occur.
Note: Digital status tags can have single or double bit addresses. Information on single and double bit digital inputs can be found in Single Bit and Double Bit Digital Inputs.
(Click title to expand text)
Select the communication driver tag from which data will be read.
The tag button to the right of the field opens the tag browser, from which you can either select an existing communication driver tag or add a new one. The X button will clear the field. Right-clicking on a tag in the field will open a dialog from which you can the driver`s properties.
The Bit 0 Address property is the address of the low order bit for this tag in the I/O device. If this is a single bit digital tag, this is the field that specifies the address of that bit. The reported value of this digital tag is the data at this address plus two times the data at the Bit 1.
Note: If a data logger is being used on a tag, it can only be for a single bit address.
The Bit 1 Address property is the address of the high order bit for the digital input in the I/O device. If this is a single bit digital input, this field should be left blank.
Provide the frequency, measured in seconds, that the I/O device should be scanned for new data.
If checked, the field Bit 0 Address becomes History Address and the field History Scan Interval is enabled.
If set, then the Bit 0 address becomes optional. This field provides a means of reading values as recorded by a data logger.
If both the Bit 0 address and the history address are provided, then the bit 0 address will be polled for data at the interval set by the Scan Rate, but the values read from the data logger will overwrite the values logged by this tag when it is updated.
The history address takes the form DLx:y where 'DL' represents a data logger, x is the data logger address (from 1 to 16) and y is the field number in the logger to be read (from 1 to 8).
Sets the time between polls of the history data logger. If a History address has been set, but this field is left blank, then it will default to the value set in the Scan Rate field. The recommended value for this field is 60 seconds. Lesser values may cause communications to slow down.
This optional field allows you to provide a constant value that will be used instead of input read by the communication driver. It is commonly used when testing a new Analog Input tag when application is not attached to a live data source. Tags that are using manual data are marked on screen by a flashing exclamation mark.
The Off Text property enables you to configure text that will be displayed in some of the tag's drawing methods when the value of this tag is 0 or false/off.
The On Text property enables you to configure text that will be displayed in some of the tag's drawing methods when the value of the tag is 1 or true/on.
If the Invert Input checkbox is selected, the value of the tag being used as the data source is reversed (i.e. a 1 becomes a 0 or a 0 becomes a 1) before it is written to the I/O device.