Configuration file

Overview

Almost everything you need day to day is reachable from the viewer: interfaces, signals, profiles, recording. This page is for the rest — the settings that only exist in the configuration file, and the exact field names and defaults behind the dialogs.

CONNECT reads two files:

File	Location	Holds
connect-config.json	%PROGRAMDATA%\realvirtual\CONNECT\	Everything about your plant: interfaces, signals, bridges, profiles, recording, update preference
appsettings.json	next to the executable	How the process itself is hosted: port binding, API key, allowed origins, log level

The split matters when you move an installation: connect-config.json is the one worth backing up and carrying over. appsettings.json belongs to the machine it runs on.

Caution

Edit the files while the gateway is stopped. CONNECT writes connect-config.json itself whenever you change something in the viewer, so a running gateway can overwrite your edits.

When a change takes effect

Not everything needs a restart, and knowing which is which saves a lot of unnecessary downtime.

Change	Takes effect
Interface, signal, bridge and profile changes	Immediately — the affected worker restarts on its own
InfluxDb settings	Immediately
McpAllowWrite, McpClientRemoteAllowed	Immediately — both are read per tool call
McpEnabled	At the next gateway start — it decides whether the endpoints are served at all
WebSocket port	At the next gateway start
Anything in appsettings.json	At the next gateway start

Global settings

These sit at the top level of connect-config.json.

Field	Default	What it does
WebSocket.Port	5100	Port for the REST API, the WebSocket and the MCP endpoint. Change it if 5100 is taken.
WebSocket.PublishIntervalMs	10	How often changed signals are pushed to connected viewers. Raising it lowers network load at the cost of a less smooth picture.
McpEnabled	true	Serves the MCP and WebViewer bridge endpoints, which is what lets realvirtual WEB and AI clients talk to the gateway.
McpAllowWrite	true	Lets those clients change signals rather than only read them.
McpClientRemoteAllowed	false	Allows non-loopback clients on the MCP endpoint. Leave it off unless you deliberately want remote tool access — see Remote access.
ActiveProfile	(empty)	Name of the profile the current live configuration came from.
SchemaVersion	(set by CONNECT)	Tells CONNECT which config generation this file is. Do not set it by hand.
Update.Enabled	true	Whether this installation offers updates at all. When off, the update endpoints refuse — it is a real switch, not a hidden button.
Update.Channel	(empty)	stable or beta. Empty means the channel this build came from, which is what keeps an installed beta from being compared against stable forever.

Recording lives under InfluxDb and is documented with its own table in Data recording.

Interfaces

Every entry in Interfaces describes one connection to a controller. These fields apply to all protocols:

Field	Default	What it does
Id	—	Your name for the interface. Bridges and mappings refer to it, so keep it stable.
Type	—	Protocol, for example OpcUa, S7, MQTT, TwinCat, Modbus.
Enabled	true	Set to false to keep a configured interface without connecting it.
UpdateCycleMs	50	How often the interface polls. The floor for how fresh values are.
ReconnectDelaySec	10	Wait between reconnect attempts after a connection drops.
AllowWebToPlc	false	Security gate. While off, values written from the browser are accepted and discarded instead of reaching the controller. Turn it on deliberately, per interface, and only where the browser is meant to command the machine.

Connection fields depend on the protocol: Endpoint for OPC UA, IpAddress plus Rack and Slot for S7, BrokerUrl for MQTT. Protocols with more settings carry their own block, listed below.

Note

AllowWebToPlc is the single most important field on this page. It is off by default, and it is what stands between a browser tab and a moving machine.

OPC UA

Set on the interface itself rather than in a nested block:

Field	Default	What it does
SubscriptionPublishingIntervall	20	Publishing interval in milliseconds — the floor for push latency on subscribed nodes.
MaxNotificationsPerPublish	50	Cap of notifications per response. 0 uses the server default.
MaxNumberOfNodesPerSubscription	0	Nodes bundled into one subscription; further subscriptions are created beyond it. 0 means one subscription for everything.

TwinCAT ADS

Block TwinCat:

Field	Default	What it does
NetId	—	AMS Net ID of the target system.
AdsPort	851	ADS port. 851 is the first PLC runtime.
Mode	SumCommand	Read strategy. Sum commands batch many symbols into one request.
MaxSubCommands	1000	Symbols per sum command.
RouteHostIp	(empty)	IP used for the ADS route when it cannot be derived.
UseEmbeddedRouter	true	Uses the built-in router, so no TwinCAT installation is required on the gateway machine.
RouterLocalNetId	(empty)	Local Net ID of the embedded router.
WriteAllInputsOnStart	false	Writes all inputs once at startup.
ReadAllOutputsOnStart	false	Reads all outputs once at startup.
RegExImportSignals	(empty)	Regular expressions selecting which symbols to import.
RegExSkipSignals	(empty)	Regular expressions excluding symbols.
RegExSymbolIsInput	(empty)	Regular expressions marking symbols as inputs when the direction cannot be derived.

Modbus TCP

Block Modbus:

Field	Default	What it does
Host	—	Address of the Modbus device.
Port	502	TCP port.
UnitId	1	Slave or unit identifier.
IsServer	false	Run as server instead of client, so a PLC can connect to CONNECT.
WordOrder	ABCD	Byte order for multi-register values. Wrong order is the usual cause of nonsensical numbers.
Transport	Tcp	Transport variant.

EtherNet/IP

Block EthernetIp:

Field	Default	What it does
Gateway	—	Address of the PLC.
Path	1,0	CIP routing path to the CPU.
PlcType	ControlLogix	PLC family.
TimeoutMs	5000	Request timeout.

Bosch Rexroth ctrlX

The native Data Layer connection uses block CtrlXDataLayer:

Field	Default	What it does
Address	—	Address of the ctrlX CORE.
Port	443	HTTPS port.
Username, Password	(empty)	Credentials for the device.
AllowUntrustedCertificate	false	Accepts a self-signed certificate. Convenient on a test bench, unwise in production.
PublishIntervalMs	100	Push interval for subscribed nodes.
SamplingIntervalUs	0	Sampling interval in microseconds. 0 uses the device default.
KeepaliveIntervalMs	60000	Keepalive interval.
ErrorIntervalMs	10000	Wait before retrying after an error.
QueueSize	100	Node queue depth.
QueueBehaviour	DiscardOldest	What happens when the queue is full.
ValueChange	StatusValue	Which changes count as a change worth publishing.
UseStatelessSubscription	false	Stateless subscription mode.
MaxSubscriptionNodes	500	Nodes per subscription.
BrowseRootPaths	(empty)	Restricts browsing to these subtrees, which keeps import manageable on a large device.
StableConnectionSec	30	How long a connection must hold before it counts as stable.
TokenTtlMinutes	10	Lifetime of the acquired access token.

The bridge tunnel variant uses block CtrlX with Address, UseSsl (true), Username, Password, BridgePath (/ctrlx-rv-bridge/ws), DirectPort (8080) and TokenTtlMinutes (10).

Keba

Block Keba:

Field	Default	What it does
Host	—	Address of the controller.
HttpPort	80	HTTP port.
WsPort	8080	WebSocket port.
Username, Password	(empty)	Credentials.
ImportRootPaths	SYS	Subtrees offered for import.
CycleTimeMs	100	Polling cycle.
UseOnChange	true	Transmits on change instead of every cycle.

Festo AX / PLCnext

Block Festo:

Field	Default	What it does
Host	—	Address of the controller.
Port	41100	Port.
UseTls	false	Encrypts the connection.
Username, Password	(empty)	Credentials.
UseSubscription	true	Subscribes instead of polling.
SubscriptionCycleMs	100	Subscription cycle.

Bridges between interfaces

Two mechanisms move values from one interface to another. Both are configured in the viewer; the fields are listed here for completeness.

Mirrors copies all signals of a source interface into an output sink — MQTT or shared memory. Names stay identical.

Field	Default	What it does
Enabled	true	Switches the rule off without deleting it.
SourceInterfaceId	—	Interface whose signals are mirrored.
TargetInterfaceId	—	Sink interface. Must be MQTT or shared memory.
SignalPattern	*	Glob filter on signal names, so you can mirror a subset.
TopicPrefix	(empty)	MQTT only: prefix in front of the signal name to form the topic.

Mappings connects one signal to one other signal, across any two interfaces.

Field	Default	What it does
Enabled	true	Switches the mapping off.
SourceSignal	—	Signal that is read.
DestSignal	—	Signal that is written.
Coercion	Strict	Strict requires the same value kind. Coerce allows the safe widenings (bool↔int, int→float) and still rejects the ambiguous ones.

Feedback loops are suppressed: a value written by a mapping is tagged, so mapping A→B and B→A does not oscillate. A mapping that targets a real controller still obeys that interface’s AllowWebToPlc.

Profiles

A profile is a named snapshot of interfaces, mirrors and mappings. Switching profiles writes the current set back into the previously active profile first, so switching never loses configuration.

Field	What it does
Name	Name of the profile.
Model	Optional GLB model name. When a model of that name becomes active, this profile is activated with it — so a model always runs with the configuration it belongs to. The models/ prefix and the .glb ending are ignored when matching.
Interfaces, Mirrors, Mappings	The snapshot itself.

Host settings

appsettings.json sits next to the executable and controls the process rather than the plant.

Field	Default	What it does
Urls	http://0.0.0.0:5100	Address the gateway binds to. 0.0.0.0 accepts connections from the network; 127.0.0.1 restricts it to the local machine.
ApiKey	(empty)	Key required by every route except /health. The access rule is loopback client or valid key, so a local viewer keeps working while remote access needs the key.
Dev.ApiKey	(empty)	Second key, for remote development only. Leave empty unless you develop realvirtual WEB across two machines — it also needs the tray switch Allow remote access (dev), and it grants more than ApiKey does, including running the test command on this PC.
AllowedOrigins	["*"]	Browser origins allowed to call the API. Narrow this when the gateway is reachable beyond the local machine.
Logging.LogLevel.Default	Information	Raise to Debug while chasing a problem, lower to Warning for quiet operation.

Caution

ApiKey, Dev.ApiKey and any controller password are stored in plain text. Anyone who can read these files can reach your controllers — protect them with file permissions, and never put them in a shared folder or a repository.

See also

• Interfaces and signals — the everyday way to configure all of this
• Protocols — what each protocol can do
• Data recording — the InfluxDb block
• Remote access — API key, origins and reaching the gateway from another machine
• Troubleshooting — when a connection will not come up