Tags
The tag page card by card: the header and verbs, General, Source with the fields of every driver, Conversion, Live value with the write field, and Used by with Replace all.
A tag is one addressable point on a device: an address on the wire, a data type, and the conversion that turns the raw reading into the engineering value. Select a tag row under a device, or press Open on a row of the device's Tags grid, to open its page. View connector reads it; Configure connector edits it; Calibrate tags edits the Calibration stage alone.
The header
A live dot (green while the tag has a value, amber when the value is a stand-in or the Limits stage raised a fault, grey otherwise), the tag's name, and under it the tag's address, Connector.<Driver>.<Folders…>.<Device>.<Tag>, which is what Logic and dashboards type. Below, when they apply: a caution note with the validation hint (a blank name, a missing address, a factor of 0) and the last error in red.
The command bar
| Command | What it does | Greyed when (situation) | Not drawn when (role) |
|---|---|---|---|
| Copy value | Copies the engineering value as displayed to the clipboard ("Copied value of 'Temperature' to the clipboard."). | Never. | Never. |
| Enable | Puts the tag back into acquisition and the live address space. | Already enabled, or the station refuses mutations. | Without Configure connector. |
| Disable | Withdraws the tag from acquisition and the live address space; the device keeps polling its other tags. | Already disabled, or the station refuses mutations. | Without Configure connector. |
| Delete tag (danger ink, on the right) | Asks "Delete 'Temperature'? This removes it from 'Furnace'. This cannot be undone.", deletes, and selects the device. | The station refuses mutations. | Without Configure connector. |
Every card autosaves as described on Connector. The General and Source cards are held inert for a role without Configure connector, with the note "Changing the Connector requires the “Configure connector” permission." on top.
The General card
| Field | What it is | Values / default | Effect |
|---|---|---|---|
| Tag name | The point's name; the last segment of both the wire key and the address. | Required. | Typing previews how many references the rename carries; committing rewrites them: "Tag renamed and 2 references updated." Blank is refused: "Tag name is required." OCPP tags must end in Meter or Status: "OCPP tag names must end in 'Meter' or 'Status' (e.g. Connector1Meter)." |
| Data type | The OPC UA scalar type the embedded server exposes. | Boolean, SByte, Byte, Int16, UInt16, Int32, UInt32, Int64, UInt64, Float, Double, String, DateTime, Guid, ByteString, narrowed to what the driver marshals; Float by default where the driver has it, else the first type it offers. | Changing it snaps what depends on it: a NaN limit action becomes Null on a type that cannot hold NaN, the NaN policy resets to pass-through on a non-numeric type, a simulated signal kind incompatible with the type is replaced by the type's default, and a Modbus register class crosses the bit/register boundary with the type. The Conversion card changes shape with it. |
| Access | Whether the station reads, writes, or both. | Read only, Write only, Read and write; Read only. OCPP, Matter and LoRaWAN offer Read only alone. | Read and write and Write only draw the write field on the Live value card; a Write only tag is not polled and does not count toward device health. |
| Unit | The engineering unit, free text. | Empty. | Shown beside every stage result and the engineering value, and wherever the value is displayed. |
| Poll interval (ms) | A per-tag override of the device's poll interval. | 0 (use the device default); a negative value is saved as 0. | Hidden for Mitsubishi MC, BACnet, IEC 61850, OCPP and LoRaWAN, which ignore it. |
The Source card
"Where this tag's value comes from, and the latest raw reading." The fields depend on the driver; the driver pages explain the semantics, this is the inventory as the panel draws it.
Free-text address
Drivers addressed by a token you type show one field, labelled per driver: Node id (OPC UA), Symbol (Beckhoff ADS), Device address (Mitsubishi MC), MMS path (IEC 61850), Controller tag (Rockwell), Resource path (Redfish), PI path (AVEVA PI), Path (HTTP), with the driver's hint under it. The field is required for these drivers: "Node id is required for this driver."
Typed fields per driver
| Driver | Fields |
|---|---|
| Modbus TCP, Modbus RTU | Register class (HoldingRegister, InputRegister, Coil, DiscreteInput; the default follows type and access: a read-only Boolean is a DiscreteInput, a writable one a Coil, a read-only number an InputRegister, a writable one a HoldingRegister) and Register number (0-based). |
| Siemens S7 | Area (DataBlock, Merker, ProcessInput, ProcessOutput, Timer, Counter), DB number (DataBlock only), Start byte, Bit (0-7) (Boolean tags), Max length (blank = 254) (String tags). |
| Rockwell | Offset in tag (bytes, bits for BOOL), after the Controller tag field; 0 is the start of the tag. |
| BACnet | Object type (AnalogInput, AnalogOutput, AnalogValue, BinaryInput, BinaryOutput, BinaryValue, MultiStateInput, MultiStateOutput, MultiStateValue) and Instance. The present value is what is read. |
| OCPP | Connector (the connector number, 1 by default), with the note "Name the tag …Meter (energy reading) or …Status (connector state)." |
| Redfish | JSON pointer (blank = whole document), "e.g. /Temperatures/0/ReadingCelsius", after the Resource path. |
| Matter | Output (endpoint) and Attribute, two numbers; the tag name is the cluster to read, spelled as the catalog spells it (On/Off, Level Control, Temperature Measurement), and carries no colon. |
| LoRaWAN | Address by Cayenne LPP channel/type (checkbox), Channel / payload offset, LPP type code (with LPP on), Bitmask (hex, blank = none), Multiplier (blank = none). |
Wire length and byte order
| Field | Shown for | What it is |
|---|---|---|
| Quantity (registers, blank = auto) | Modbus, String tags only | How many 16-bit registers to read; blank reads 4. Other Modbus types take a fixed width (one register for Boolean, two for Int32 and Float), so the field is not drawn for them. |
| Read length (bytes, blank = auto) | Beckhoff, Mitsubishi, IEC 61850, LoRaWAN | The byte count; blank derives it from the type: 1 for Boolean, Byte and SByte; 2 for Int16 and UInt16; 4 for Int32, UInt32 and Float; 8 for Int64, UInt64 and Double; 16 for String; 4 otherwise. |
| Most significant byte first | Modbus (numeric tags), LoRaWAN | Which end of the value comes first on the wire. On by default for Modbus, off for LoRaWAN. Modbus defines no byte order for text, so a Modbus String tag is not offered it. |
| Most significant word first | Modbus | Which 16-bit half leads in a two-register value. On by default. Not offered for LoRaWAN, whose payload has no word to put first. |
Source address (wire)
Every non-simulated tag ends the field group with a read-only preview of the address the driver actually receives, assembled from the fields above and the device's connection fields: 0?quantity=2 for a Modbus register, DB1?0 for an S7 byte, Program:Main.Counter?0 for a Rockwell tag, MAIN.fValue?4 for an ADS symbol, 0,3 for a BACnet object, ocpp://<charge point>/<connector>, <resource>#/Temperatures/0/ReadingCelsius for Redfish, <DevEUI>/<channel>/<lpp>?quantity=<n> for LoRaWAN, <endpoint>/<attribute> for Matter, and the token itself for OPC UA, AVEVA PI and HTTP (prefixed with the device's resource path).
Simulated signal parameters
A Simulated tag has no address field: its name is the point. Instead: Signal kind, a list narrowed to the shapes the data type can drive, each with a small picture of the shape beside its name (Sine, Ramp, Random walk and Counter for numbers; Toggling boolean for Boolean; Enumerated text for String; Clock for DateTime; Random GUID for Guid; Random bytes for ByteString; Setpoint hold and Pulse for any type). Default value appears for Random walk, Counter and Setpoint hold, as a text field, a "Default is on (true)" checkbox for Boolean, or a date field for DateTime. States (semicolon-separated) appears for Enumerated text: "e.g. Run;Stop;Pause (cycles one step every 3 s)." Shape parameters the panel does not edit (a sine's band and period, a pulse's hold) travel with the tag unchanged. The Simulated page lists every parameter.
Raw value
The card closes with the latest raw reading as the driver delivered it, before any conversion; a dash when there is none.
The Conversion card
"How the raw value is turned into the engineering value." The card is drawn for numeric, Boolean and String types; DateTime, Guid and ByteString pass through unchanged and show no card.
For a numeric tag the card is the staged pipeline, top to bottom: Raw value, then Scale (Angular (×), Linear (+), a Two-point button), Calibration (the same three), Invalid reading (two policies), Limits (Min, Max, Action), Decimals (Decimals) and Engineering value with the unit. Each stage from Scale on carries a checkbox in its head that turns the stage on or off, and a result on the right: = value when the stage applies, → value when it is bypassed. A limit fault turns the Limits stage red and prints "Value 130 is outside the limits [0, 100]." under the card. The math, the defaults and the policies are on The value pipeline; the two-point assistant and the permission split between Scale and Calibration are on Calibration.
A Boolean tag shows Invert (report the negation of the raw value), the Result, and the Invalid reading policies. A String tag shows Substring start and Length (blank = to end), the Result, and the Invalid reading policies.
Past Scale and Calibration, the numeric stages and the Boolean and String transforms are ordinary configuration: Configure connector edits them, everyone else reads them.
The Live value card
| Item | What it shows |
|---|---|
| Current value | The engineering value, formatted with the tag's decimals and unit; a dash when there is none. |
| Stand-in note | When the value is not a measurement: "Replacing a missing measurement.", "Last good value, held while the device is not answering." or "Replacing a failed read.", per the Invalid reading policies. |
| Source timestamp | When the equipment took the reading. While a read is failing the label turns to Last attempt and the stamp is the attempt's; while the last good value is held, the stamp stays that reading's. |
| Application timestamp | When the embedded server received it. |
| Write value | For a Read and write or Write only tag, and Configure connector only: a text field (a checkbox "On (true)" for Boolean, a date field for DateTime) and Write. "Enter the engineering value; scaling and invert are reversed before writing." The status line reads "Value written.", "Write failed.", "Enter a value to write." or "Value could not be converted." |
Write is greyed with its reason while a run holds the station or the runtime is stopped. A write is refused as "Write failed." when a Logic source lock holds the tag, when the driver rejects it, or when the device is not connected. What is reversed before the raw value leaves is on The value pipeline.
The Used by card
"Channel bindings, Logic definitions and dashboard components that reference this tag." The table lists every reference with Kind (Channel, Stop interlock, Automation, Variable, Action, Alarm, Dashboard), Location (the model or dashboard that holds it; empty for the top-level Logic kinds) and Name. With none, "Not referenced by any channel or property." The lookup is advisory: a failure leaves the grid empty.
For Configure connector the card adds the replace apparatus: a picker listing every other tag in the live address space by address, a Replace all button, and a per-row replace action. Replace all rewrites every listed reference to the picked tag in one all-or-nothing batch ("4 reference(s) now use Connector.Simulated.Air.Pump.Flow."; "No references to replace."); the row action rewrites that one ("'Furnace temperature' now references Connector.Simulated.Air.Pump.Flow.", or "The reference changed in the meantime. Refresh and retry." when it moved under you). A Stop interlock or Automation reference is Process structure, so replacing it needs Manage process on top: "Replacing a Unit interlock source requires Process manage permission." and "Replace all includes a Unit interlock source and requires Process manage permission."
What the tag page does not do
The tag's device and driver are fixed; move a point by creating it on the other device and using Replace all. Only one tag's stages are edited at a time here; multi-row edits are the device grid's mass edit, described on Devices. There is no history or trend on the page: the live dot, value and timestamps are the current sample, refreshed once a second.