IEC61850

IEC 61850 is the communication standard of substation automation, used by protection relays, bay controllers and the plant controllers of PV parks and battery storage systems. EnvisionSCADA acts as an IEC 61850 client: it connects to the MMS server of an IED (intelligent electronic device) on TCP port 102, as defined by IEC 61850-8-1, and reads, writes and operates the data of the IED's data model.

Each IEC61850 device represents one IED and holds one MMS association to it. The variables of a device can address every logical device of that IED, so create one device per IED, not one per logical device. IEDs accept a limited number of simultaneous associations, and one device per IED keeps the number that EnvisionSCADA uses at one.

Values arrive in two ways. A variable inside the data set of an enabled report control block is updated by the reports of the IED, which send changes as they occur. Every other variable is polled at the Poll Interval of the device. Values carry the quality and the time stamp of the IED, so events are stored in the historian with the original process time. See Reports and Polling.

Variables reference the data of the IED by IEC 61850 object reference with the functional constraint in brackets, for example IED1LD0/MMXU1.TotW.mag.f[MX] for the total active power of a measurement unit. Variable names are free-form: with the {Device} replacer, {Device}.Breaker1_Position on a device named IED1 is referenced as IED1.Breaker1_Position, and a plain name such as Feeder1_TotW is referenced as it is.

The data model does not have to be typed by hand. Browse on the IEC61850 Variables page reads the data model online from the IED, and Import SCL on the IEC61850 Devices page creates a device and its variables from the ICD, IID, CID, SCD or SED file of the IED engineering.

Device Settings

Each IEC61850 device represents one IED. Configure the connection to the MMS server of the IED, the OSI addressing of the association, the report control blocks, the command settings and the diagnostics options.

Create a new device with the Add button in the toolbar, or from an SCL file with Import SCL as described under Import SCL. The Add device dialog contains the device settings organized in the sections General, Connection, OSI Addressing (advanced), Reports, Commands and Diagnostics, with default values already filled in. Enter at least the Name and IP Address and press Create.

The device row shows Enable, Name, IP Address, Port, Poll Interval (ms), Template, Description and Simulation directly and these values can be edited in place, and Status shows the Channel State of the device. All other device settings are also available as table columns, which are shown with Columns as described in the Configuration Tables article. Press the Settings icon on a device row to open the Edit device dialog, which contains the same sections and all settings of the device. Press Save to apply the changes.

The table lists the general and connection settings. For the numeric settings the Example column shows the default value.

Device Advanced Settings

The following settings are available in the OSI Addressing (advanced), Reports, Commands and Diagnostics sections of the Add device and Edit device dialogs. The defaults of the OSI Addressing (advanced) section suit most IEDs, and Import SCL fills them from the SCL file. The sections OSI Addressing, Reports and Polling, and Writing and Controls below describe how the settings work together.

OSI Addressing

An MMS association runs over the OSI upper layers, and the IED can check the OSI addressing of the client before it accepts the association. The values that address the IED belong to its access point and are listed in the Communication section of the SCL file, in the Address of the connected access point. Import SCL copies them into the device; enter them by hand only for a device created with Add. The selectors may be entered with spaces, colons or dashes between the bytes, which are removed when the device is saved.

The local values identify EnvisionSCADA to the IED. Change Local AP Title and Local AE Qualifier only for an IED that admits clients by AP title, and enter the values configured for this client in the IED then. Authentication Password in the Connection section is sent with the association request when the IED requires ACSE password authentication.

When the IED refuses the association although IP Address and Port are correct, compare these settings with the Address of the access point in the SCL file first.

Reports and Polling

Report control blocks are configured in the IED and listed, one per line, in Report Control Blocks of the device. A buffered report control block ([BR]) keeps the events that occur while no client has it enabled and sends them once the client enables it again. An unbuffered report control block ([RP]) sends changes only while it is enabled.

When the association is established, EnvisionSCADA processes the lines of Report Control Blocks in order. For each line it:

• reads the attributes of the report control block and the members of its data set,
• reserves the report control block where the IED supports a reservation (Resv for an unbuffered, ResvTms for a buffered report control block),
• writes the configuration: the optional fields of the report, the trigger options of the IED extended with general interrogation and, when Integrity Period (ms) is not 0, with integrity and the integrity period. A configuration write that the IED refuses keeps the value configured in the IED and is logged,
• enables the report control block and sends a general interrogation, so the IED reports every member of the data set once.

A variable whose address lies inside a member of the data set of an enabled block, with the same functional constraint, is updated by the reports of that block. Every other variable is polled every Poll Interval (ms): the value is read together with the quality q and the time stamp t of its data object, in batched Read requests sized by the negotiated PDU size. After every association the System Log shows how the variables are served, followed by the number of controls and of variables that cannot be used, when there are any:

12 points by report (2 reports), 3 points polled, 2 controls, 1 not available (see the device log)

An IED usually offers several instances of one report control block, one per client, for example urcbMX01 and urcbMX02. Separate them with | on one line, and EnvisionSCADA uses the first instance it can reserve. A report control block that another client has reserved or enabled is skipped.

IED1LD0/LLN0.brcbST01[BR]
IED1LD0/LLN0.urcbMX01[RP]|IED1LD0/LLN0.urcbMX02[RP]

When no instance of a line can be reserved or enabled, the cause is logged once, the variables of its data set are polled, and the line is tried again after every new association and every 60 seconds, or at the GI Interval (s) when that is shorter. Once the line is enabled, the System Log reports that its points are updated by reports again. The System Log line after the association counts such a line as not enabled, for example 9 points by report (1 report, 1 not enabled), 6 points polled.

What a report delivers depends on how the data set is built in the IED. A data set of whole data objects, for example MMXU1.TotW with functional constraint MX, delivers the value, the quality and the time stamp of the IED together. A data set of single attributes, for example MMXU1.TotW.mag.f, delivers the value only: the variable takes the time it is received, or the TimeOfEntry of a buffered report, and the Good status, unless the q attribute is a member of the data set as well. A report contains only the members that changed, so a value change arrives without its q member; EnvisionSCADA then applies the quality that the q member reported last, and the variable keeps a status such as ConnectionLost or Warning until the IED reports a good quality. Use data sets of whole data objects for values whose events must keep the process time and quality.

After a start of EnvisionSCADA, the first enable of a buffered report control block makes the IED send the events it buffered, with their own time stamps, followed by the current state from the general interrogation. This is how events that occurred while EnvisionSCADA was stopped reach the historian. Because the first enable after a start resumes nothing, a restart can deliver buffered events a second time. A reconnect while the device keeps running resumes the buffer after the last report that EnvisionSCADA processed, so the reports that were in transit when the connection broke are sent again. Disabling and enabling the device, and saving a change to the device or to one of its variables, start the device again, which behaves like a start of EnvisionSCADA.

Integrity Period (ms) makes the IED report all members of the data set periodically, and GI Interval (s) makes EnvisionSCADA request a general interrogation periodically. Both refresh every member regardless of changes.

Findings that mean events may be missing from the historian and the event list are logged at every Verbose level, once per report and association: a gap in the sequence numbers of an unbuffered report, a buffer overflow reported by the IED (BufOvfl), and a resume point that the IED refuses, typically because the entry left the buffer of the IED during the interruption. The general interrogation that follows restores the current state. Some IEDs report a buffer overflow in the first report after every enable without a resume point, so this line can appear at a connect although no event was lost.

When a report shows that the data set definition changed in the IED, by its configuration revision, its data set name or its number of members, EnvisionSCADA logs it, reads the data set again and sends a general interrogation. Variables then move between reports and polling as the new data set requires.

When no traffic has passed for 60 seconds, EnvisionSCADA reads the first variable of the device to check the association. When that read is not answered within Timeout (ms), the device goes Offline and reconnects.

Variable Settings

Variables are added per device. Each variable maps one data attribute or one control of the IED to a named variable in the EnvisionSCADA namespace.

Create a new variable with the Add button in the toolbar, or from the data model of the IED with Browse as described under Browse. The Add variable dialog organizes all variable settings in the tabs General, Scaling, Historian, and Gateway, with default values already filled in. Enter at least the Name and Address on the General tab, select the Type and press Create. When the variable is created on a template device, it is also created on all instance devices that use the template. On a template device, start the Name with the {Device} replacer, so that each instance device gets its own variable. The Name must resolve to a different variable on each device; this is checked for every instance device before anything is saved, when a variable is created and when it is renamed.

The variable row shows Enable, Name, Asset, Address, Type, and Description directly and these values can be edited in place, and Live Value shows the current value of the variable. Press the Settings icon on a variable row to open the Edit variable dialog, which contains the same tabs and all settings of the variable. Press Save to apply the changes. Changes made on a template device are also applied to the matching variable on all instance devices, while each instance keeps its own Modbus Address value. All other variable settings, among them Command Mode and Command Checks, are also available as table columns, which are shown with Columns as described in the Configuration Tables article.

Addressing

The Address is an IEC 61850 object reference with the functional constraint in brackets at the end:

LD/LN.DO[.SDO][.DA[.BDA]][FC]

LD is the logical device as the IED names its MMS domain: the IED name followed by the logical device instance, for example IED1LD0 for IED IED1 and instance LD0, unless an Edition 2 IED gives the logical device its own name (ldName). Enter it exactly as the IED shows it; Browse and Import SCL fill it in. LN is the logical node, for example MMXU1 or XCBR1. It is followed by the data object (DO) with optional sub data objects (SDO), and by the data attribute (DA) with optional sub attributes (BDA). The functional constraint (FC) is required. An address in the MMS notation with $, as an MMS browser shows it, for example IED1LD0/XCBR1$ST$Pos$stVal, is refused with a hint to the notation above.

A control is addressed at the data object with functional constraint CO, for example IED1LD0/CSWI1.Pos[CO]. EnvisionSCADA builds the control structures Oper, SBOw and Cancel itself, so the address ends at the data object.

Writeable can be set on CO, SP, CF, DC and SV variables. A CO variable is operated from pages, actions, scripts and the API with Writeable cleared; Writeable lets the gateways operate it as well. The values of ST and MX attributes are changed in the IED through substitution (SV) or operated through a control (CO).

Data Types

Select the Type that holds the basic type of the attribute in the IED. The table shows the Type that Browse and Import SCL propose for each IEC 61850 basic type. The type of the attribute in the IED, read when the device connects, drives the decoding, and the Type decides how EnvisionSCADA stores the value. A Type that cannot hold the value of the IED is reported when the device connects: the variable shows the FormatError status and the System Log shows one line for it. A control on an SPC or DPC, whose ctlVal is BOOLEAN, requires Type BOOL: 1 or true operates on or close, 0 or false off or open, and any other value is refused. INT on such a control, for example to match the Dbpos values of the position (1 off, 2 on), is reported as FormatError when the device connects.

Browse and Import SCL list the attributes of the basic types in the table. Structures and the other basic types, such as INT128, Check, EntryTime, Currency, EntryID and the bit strings of control blocks (TrgOps, OptFlds), have no Type and are left out of the lists.

Quality and Time Stamps

IEC 61850 attaches a quality q and a time stamp t to the attributes of a data object. EnvisionSCADA applies the q and t of the data object that encloses the attribute of a variable to its value, for reported and for polled variables, and sets the variable status from the quality.

The value is kept in every case, so a page shows the last value together with its status. See the Variable Status article.

To work with a single quality flag, for example in an alarm, add a variable with Type WORD on the q attribute, for example IED1LD0/XCBR1.Pos.q[ST]. The WORD holds the quality bits with bit n of the IEC 61850 bit string as the value 2 to the power n. The two validity bits are bits 0 and 1 of the bit string, so validity reads 0 for good, 2 for invalid, 1 for reserved and 3 for questionable in the lowest two bits of the WORD.

The time stamp t of the data object becomes the time stamp of the variable, for reports and for polls. The IED moves t when a value attribute such as stVal or mag, or q, changes. Attributes that change without moving t, for example instMag of a measurand or stSeld of a control, take the time a change is received, so every change reaches the historian with its own time. An attribute without a t in its data object, and a value from a data set of single attributes, takes the time it is received, or in a buffered report the TimeOfEntry of the report, so the values of a buffered replay keep the time at which the IED recorded them.

The time stamp passes a plausibility check, and the TimeOfEntry passes the same check. A time before the year 2000, or more than one minute ahead of the EnvisionSCADA server, is replaced by the receive time and reported once in the System Log. A time in the past is kept, so buffered events keep their original time. A time stamp whose time quality reports a clock failure is replaced by the receive time and logged once. A time stamp whose time quality reports that the clock is not synchronized is kept and logged once.

EnvisionSCADA rounds the time of the IED to the microsecond, which restores the time the IED encoded, for example 202 ms instead of 201.99996 ms. The text of a STRING variable on a t attribute is rounded the same way. The historian stores the time to the millisecond, as for every source. Value, quality and time stamp of one data object are applied together.

Writing and Controls

A variable is written from runtime pages, actions, scripts and the API, and by external systems through the gateways when Writeable is enabled. The Converter and the scaling are applied in reverse before the value is encoded in the type of the IED. SP, CF, DC and SV variables are written with a plain MMS write, and the variable takes the written value once the IED confirms the write. A write to a variable of any other functional constraint, for example ST, MX, EX or SG, is refused and logged, and the status of the variable stays unchanged.

The standard write actions behave as follows: Set writes 1, Reset writes 0, Toggle inverts the last value received from the IED, and Momentary On sends true to a control, with the pulse decided by the pulse configuration of the control object in the IED. Toggle requires Type BOOL, and Momentary On requires a control (CO) with Type BOOL.

A CO variable is a control and is written through the control model of the control object. EnvisionSCADA reads the control model (ctlModel) and the select timeout (sboTimeout) from the configuration attributes of the control object when the device connects, so the IED decides the sequence. When the IED does not answer ctlModel, EnvisionSCADA derives the control model from the control structure: SBOw gives 4, SBO gives 2, and Oper alone gives 3, so a command is confirmed only by a CommandTermination. The System Log reports the derived control model when the device connects. A control object with sboClass operate-many keeps its selection after the operate; EnvisionSCADA sends a Cancel after the confirmed operate, so the control object is free for other clients:

The variable takes the new value only after the completion in the table, so a displayed value is always a value that the IED accepted. A refusal, a negative CommandTermination or no CommandTermination within Command Termination Timeout (s) ends the write: the variable keeps its previous value and shows the FormatError status, and the System Log names the AddCause that the IED reported, for example blocked by interlocking (AddCause 10). Without a CommandTermination the log line adds that the command may have executed, because the IED had accepted the Oper. A request that the IED does not answer within Timeout (ms) sets the device Offline, as for every request. For a write from a page, the refusal also appears in a message on the page and in the Reason column of the Write record in the Audit Trail. A write through the Runtime API (POST /API/WriteVariable) or the MCP WriteVariable tool answers with the same text instead of OK, including a command whose outcome is not known because no CommandTermination arrived. When the IED refuses the Oper after a selection, EnvisionSCADA sends a Cancel, so the control object is not left selected. See Troubleshooting for the common AddCause values.

Command Checks sets the check bits of every control. The default, Interlock check, asks the IED to apply its interlocking before it operates. None asks the IED to skip its interlocking, so select None only for a control object without interlocking. Synchrocheck asks the IED to apply its synchronism check. The Test flag of a control is always sent as false.

Every control carries the Originator Category (orCat) and the Originator Identifier (orIdent) of the device. The IED checks the Originator Category against its switching authority: the local or remote setting Loc of the bay and, from Edition 2, LocSta for the station level. A control whose category does not match the active control level is refused with AddCause blocked by switching hierarchy, for example a Remote control command while the bay is switched to station control. Station control fits EnvisionSCADA as the station SCADA; Remote control fits EnvisionSCADA in the role of a control centre.

The Originator Identifier appears in the event list of the IED. For a control issued by a logged-in user, EnvisionSCADA appends the user name after a slash, for example ENVISION/operator1, cut at 64 characters. A control without a logged-in user, for example from a schedule or an alarm action, carries the Originator Identifier alone.

Command Select Timeout limits how long an operator selection is held. The IED has its own select timeout, sboTimeout, after which it drops a selection by itself. Set Command Select Timeout below the sboTimeout of the control objects, so EnvisionSCADA cancels the selection before the IED drops it. When Command Select Timeout is not below the sboTimeout read from the IED, EnvisionSCADA holds the selection for a shorter time that ends before the sboTimeout, by a quarter of the sboTimeout and at most one second, so <Variable>.Selected and <Variable>.SelectRemaining never show a selection that the IED has dropped. The System Log names the shorter hold when the device connects and with every selection. Command Termination Timeout (s) is the wait for the CommandTermination under enhanced security, after the IED accepted the Oper; raise it for switchgear that needs longer to operate.

Operator Select Before Operate

Command Mode Select before operate (operator) splits a control into two operator actions, configured on a button or another clickable object with the Select Command and Execute Command actions. Select Command selects the control object: EnvisionSCADA sends the selection, SBO or SBOw according to the control model, and waits for the IED to confirm it. The control object is then reserved at the IED and nothing has moved in the field yet. Execute Command then sends the Oper. The variable takes the new value only after the IED confirms the operate, under enhanced security after the CommandTermination.

The mode applies to control objects with the control model sbo-with-normal-security or sbo-with-enhanced-security, and it can be selected on controls (CO) only. Select Command on a control object with a direct control model is refused; the System Log names the control model when the device connects.

The reservation is held by the IED, not by EnvisionSCADA, and it is released again when the operator executes it, when the operator cancels it, or when the hold runs out, which is Command Select Timeout or the shorter time described under Writing and Controls; in the last two cases EnvisionSCADA sends a Cancel, so the control object is not left selected in the field. When the IED refuses the Oper of Execute Command, EnvisionSCADA sends a Cancel as well. When the association to the IED is lost, the selection ends and the IED releases it on its own.

A selection belongs to the operator who made it. Another user sees that the control object is selected and by whom, and cannot execute or cancel that selection. A third action, Cancel Selection, releases the control object again without operating it.

These three variables exist for every control configured for an operator selection, from the moment the device starts, so a faceplate resolves them before the first selection is made. They are read only.

Automated writes are unaffected. A Python script, a schedule, an alarm action or a gateway write to the same control performs the selection and the operate in one step, because there is no operator to pause for. The two-stage actions are available on pages only, for the same reason: they wait for a person. The exchange with the IED is identical; only the pause differs.

Build the controls once as a group symbol master with the control name as a replacer, then create one instance per control, rather than wiring the buttons per page. The selected state must always come from these variables. A local variable set by a button and cleared by a script only looks the same: it reports a selection that the IED never made and keeps counting down after the association is gone.

With Signature Required selected on the variable, the electronic signature is asked at Execute Command. Select Command and Cancel Selection run without a signature.

The result of each stage is recorded in the System Log and in the Audit Trail, with the reason of a refusal in the Reason column. The page shows the reason of a refusal in a message. A refusal by the IED also sets the variable to FormatError.

Browse

The Browse button on the IEC61850 Variables page opens the Browse dialog, which shows the data model of the IED as a tree of logical devices, logical nodes, functional constraints, data objects and data attributes. A logical device or a logical node is read from the IED when it is opened; the functional constraints, data objects and attributes of a logical node come with it. The tree lists the functional constraints ST, MX, CO, SP, CF, DC, EX, SV and SG.

Browse uses the running association of the device when the device is connected, so it needs no second association to the IED. When the device is not connected, for example while it is disabled or in Simulation, Browse opens a short-lived association with the settings of the device and closes it again afterwards. Browse is available on the primary server only.

Each attribute with a Type shows its Address, its IEC 61850 Type and the proposed Type next to the name, and has a checkbox. Under CO the data object itself is the entry to select, for example Pos under CSWI1, because a control is addressed at the data object. The search field lists the selectable entries whose name or Address contains the text, from the logical nodes opened so far; Expand All reads every logical node first and then changes to Collapse All. The checkbox in the header row selects or clears the entries shown, and the footer shows how many variables are selected. One level of the tree, as read from the IED, is limited to the first 5000 entries, and the dialog says so when the limit is reached.

Tick the entries to add and press Add Selected. Each selected entry is created as a variable with its Address and Type filled in, with Writeable cleared; select Writeable afterwards only on the variables that a gateway has to write. The result reports how many variables were added and how many were skipped because a variable with that name already exists, and lists the entries that could not be created with the reason.

The suggested Name follows the path of the attribute with dots, for example IED1LD0.MMXU1.TotW.mag.f for IED1LD0/MMXU1.TotW.mag.f[MX], and a control gets the suffix .Oper, for example IED1LD0.CSWI1.Pos.Oper. Characters other than letters, digits and underscores in a part of the path are written as an underscore. When two selected entries give the same name, the second one gets an underscore and its functional constraint appended.

With Start names with {Device}. selected, which is the default, each variable name starts with the {Device} replacer, so the same entry added on several devices, or on a template device and its instance devices, gives each device its own variable. Clear Start names with {Device}. to use the suggested Name as it is. A plain name must be unique across the whole project, and a template device with instance devices requires the {Device} replacer.

Import SCL

The Import SCL button on the IEC61850 Devices page creates a device and its variables from an SCL file of the IED engineering: an ICD, IID, CID, SCD or SED file exported from the IED configuration tool or the system configuration tool. Select the file in SCL File. The file is read when it is selected, and nothing is created until Create is pressed. The file can be up to 100 MB. A file that contains a document type declaration (DOCTYPE) is refused for security reasons; remove the DOCTYPE or export the file again from the configuration tool. The dialog also reports a file that contains no IED with an MMS access point.

An SCD or SED file holds several IEDs. When the file holds more than one IED or access point with an MMS server, select the IED and the Access Point in the lists that appear; with one, the preview appears at once.

An ICD file describes an IED type and carries the placeholder IED name TEMPLATE, while the IED itself uses the name it received in the system engineering. Enter that name in IED Name, so the addresses get the logical device names the IED shows, for example IED1LD0 instead of TEMPLATELD0. The field is filled with the IED name of the file when that name is not TEMPLATE. A logical device with its own ldName keeps that name.

Variables from selects which variables are offered. Data set members, the default, lists the attributes of the data sets of the IED, which are the variables that the reports update. The value attributes are selected; the q and t attributes are listed unselected, because the quality and the time stamp of the data object are applied to the value anyway. Whole data model lists every attribute of the functional constraints ST, MX, SP, CF, DC, EX, SV and SG, and every control (CO) of the IED; the value attributes of the data sets are selected and every other row is listed unselected. Start names with {Device}. works as in Browse.

The Device section of the preview shows Name, IP Address, Port, Remote AP Title, Remote AE Qualifier, Remote P Selector, Remote S Selector, Remote T Selector, Report Control Blocks and Description, and each can be changed before the device is created. The Name is the IED name, or the name entered in IED Name, with characters other than letters, digits and underscores written as an underscore. Port is 102. IP Address and the OSI addressing come from the access point in the Communication section; a value that the file does not carry keeps its default. Report Control Blocks lists every report control block of the IED, with the instances of an indexed report control block as alternatives separated by |. The Description is the description of the IED, or its manufacturer and type. All other device settings take their default values and can be changed afterwards in the Edit device dialog.

The Variables section lists the candidates with Name, Address, Type, IEC 61850 Type, Data Set, Description and Enumeration Values. The Name can be changed. The search field narrows the list, the checkbox in the header row selects or clears the rows shown, and a count shows how many variables are selected. Data Set names the data set that contains the attribute. Description is taken from the description of the attribute or the data object in the file. Enumeration Values shows the texts of an enumeration as number=text, for reference only: the variable stores the number. Variables are created with Writeable cleared, controls included. Two candidates with the same name are told apart by an underscore and the functional constraint appended to the second one. At most 20000 variables are listed. Warnings found while reading the file, such as skipped array attributes, are listed under Warning in the dialog.

Press Create to create the device and then the selected variables. The result names the device and the number of variables created, and lists the variables that could not be created with the reason; the device is kept in that case, and the remaining variables can be added with Browse or Add. When the device itself cannot be created, for example because the name is already in use, the dialog stays open with the reason. Changing IED, Access Point, IED Name or Variables from reads the file again.

Redundancy

In a redundant installation only the primary server associates with the IEDs. The standby server opens no association and does not browse. After a failover the new primary associates, reserves and enables the report control blocks and sends a general interrogation, so the current values are correct again. See the Redundancy article.

A reservation of the old primary can outlive it. Whether another client may take over a report control block while the reservation of the previous owner lasts differs per IED and is described in the PIXIT of the IED. Until a block is free, the variables of its data set are polled and the block is tried again every 60 seconds, or at the GI Interval (s) when that is shorter, and alternatives separated by | in Report Control Blocks let the new primary take another instance of the report at once. Buffered events that occur during this takeover can be missed; the general interrogation restores the current state.

Engineer both servers into the IED configuration. An IED can admit MMS clients by IP address, and an SCD can assign report control blocks to named clients, so both redundant servers must be part of that configuration. List one instance of each report for each server as alternatives on one line, for example IED1LD0/LLN0.urcbMX01[RP]|IED1LD0/LLN0.urcbMX02[RP].

Simulation

With Simulation selected the device does not open its association. Its variables stay available and are read and written in memory like Local variables, with a Good status, so pages, alarms and scripts can be tested without the IED. The Channel State variable of the device reads Simulation, while a connected device reads Connected, so a communication status indicator on a page should test the Channel State. Written values are held in memory only and reset when the application restarts.

Browse still reads the real IED with a short-lived association, so the data model can be browsed while the device is simulated.

Troubleshooting

The Channel State variable of the device, for example IED1.ChannelState, shows the state of the association. Build a communication alarm on it, for example IED1.ChannelState != "Connected". The ExecutionTime variable of the device, for example IED1.ExecutionTime, holds the duration of the last poll cycle in milliseconds, and 0 while every variable is updated by reports.

The following situations are the usual ones during commissioning:

When the IED refuses a control, the System Log names the AddCause from the LastApplError of the IED. The common values:

Verbose in the Diagnostics section of the device adds detail to the System Log. 0 logs connection details and errors. 1 also logs one line per MMS request and per received report, which shows the report control block sequence and every report as it arrives. 2 also logs every PDU in hexadecimal with a decoded summary. Use 1 or 2 only while commissioning or diagnosing, because they increase the log volume significantly.

Notes

EnvisionSCADA operates as an IEC 61850 client only. The communication uses MMS: reads, reports, writes and controls.

The status and the control of a switch are separate variables: for example IED1LD0/XCBR1.Pos.stVal[ST] for the breaker position and IED1LD0/CSWI1.Pos[CO] for the breaker control.

Every enabled variable of an enabled device counts as one licence point. The quality and the time stamp that arrive with a value count as part of that variable; a variable of its own on a q or t attribute counts as a point.

The IEC61850 driver is available in the Windows installation and in the Docker deployment. It needs outbound TCP connections to the IEDs only. On a test PC another tool can already hold port 102; an IED simulator then listens on another port, which is entered in Port.