Keyence KV Nodes

Read and write Keyence KV PLCs directly from pipelines over Host Link. Each operation has its own node in the Pipeline Designer (Keyence Read, Keyence Block Read and Keyence Write), plus a Keyence Read Group node that runs several reads in one node.

For connection setup, device addressing, data types and per-function fields, see the Keyence KV connection guide.

Configuration Quick Reference

Field	What you choose	Details
Parameters	Connection, Function, Function Parameters, Timeout Override	Select the Keyence connection profile, pick a function, bind parameters with expression support, and optionally override the timeout.
Settings	Description, Timeout (seconds), Retry on Timeout, Retry on Fail, On Error	Node description, maximum execution time, retry behaviour on timeout or failure, and error strategy. All execution settings default to pipeline-level values.

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Keyence Read Node

Read one typed value from a device or tag, or Count consecutive values as a list. Runs a keyence.read.device function.

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Keyence connection profile to use
Function	Selection	Yes	A keyence.read.device function from the selected connection
Function Parameters	Dynamic	Varies	Auto-populated from the function (device, dataType, count, length). See Read Device.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

quality is good when the PLC answered: an error reply (E0–E6) fails the node instead of storing a value, so a value that reached the result is the PLC's own reading.

{
  "result": {
    "device": "DM100",
    "dataType": "DINT",
    "value": 1234,
    "quality": "good"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 6, "timestamp": "2026-09-30T08:30:00Z" }
}

Field	Type	Description
result.device	string	The device or tag you read (a raw address such as DM100, or the tag name)
result.dataType	string	The type the value was decoded as
result.value	any	The decoded value (BIT → boolean, STRING → text, the rest → number); a list of values when Count is more than 1
result.quality	string	good: a PLC error reply fails the node instead of storing a value

{{ $node["Keyence Read"].result.value }}

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Keyence Block Read Node

Read many named, typed points in the fewest requests. Runs a keyence.read.block function.

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Keyence connection profile to use
Function	Selection	Yes	A keyence.read.block function from the selected connection
Function Parameters	Dynamic	Varies	The dataPoints list. See Read Block.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "count": 2,
    "values": { "count": 1234, "alarm": true },
    "quality": "good",
    "totalDataPoints": 2,
    "totalReads": 2
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 9, "timestamp": "2026-09-30T08:30:00Z" }
}

Field	Type	Description
result.values	object	Every point by its name
result.count	number	How many points were decoded
result.quality	string	good: a PLC error reply fails the node instead of storing a value
result.totalDataPoints	number	How many points were requested
result.totalReads	number	How many Host Link requests the points were merged into

{{ $node["Keyence Block Read"].result.values.alarm }}

How points are merged

Points on the same device type are sorted by address. Neighbours within a small gap share one RDS request, and a run never exceeds the PLC's per-request count limit (1000 words on KV, 256 on a KV Nano). Relays, timers and counters are read in their own requests. totalReads shows how many requests the read used.

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Keyence Write Node

Write one typed value to a writable device, or a list of values to consecutive devices in one request. Runs a keyence.write.device function.

A single relay is set or reset on its own (ST / RS), so relays the PLC changes meanwhile are never overwritten. A bit inside a data-memory word (DM100.05) is written by reading the word and writing it back with that bit changed. A write is sent once: the node does not repeat it when the PLC does not answer, and it does not run in a pipeline started by a late (replayed) input.

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Keyence connection profile to use
Function	Selection	Yes	A keyence.write.device function from the selected connection
Function Parameters	Dynamic	Varies	device, dataType, value, length. The value field supports ((paramName)) templates. See Write Device.
Timeout Override	Number (seconds)	No	Override the default function timeout

Output Structure

{
  "result": {
    "device": "DM200",
    "dataType": "REAL",
    "value": "72.5"
  },
  "_metadata": { "success": true, "functionId": "<function-id>", "durationMs": 7, "timestamp": "2026-09-30T08:30:00Z" }
}

Field	Type	Description
result.device	string	The device or tag written
result.dataType	string	The type the value was encoded as
result.value	any	The value as given (after parameter substitution)

A value the type cannot hold (70000 as WORD), a write to the read-only digital trimmer AT, or text longer than the string length fails the node before anything is sent to the PLC.

Safety first

Validate values in a Condition node before writing to equipment. A setpoint or relay can move a motor, valve or actuator immediately.

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Keyence Read Group Node

Execute multiple read functions from a single Keyence connection in one node. The read group runs the selected functions (in parallel or sequentially) and merges their results, which is ideal for collecting a line's data from one PLC without a node per function.

Merging neighbouring addresses into one request happens inside each keyence.read.block function. The connection still carries one request at a time, so parallel functions queue on the link rather than overtake each other.

Supported Function Types:

Function Name	Purpose
Read Device (keyence.read.device)	One typed value (or a list) per function
Read Block (keyence.read.block)	A batch of named datapoints per function

Node Configuration

Parameter	Type	Required	Description
Connection	Selection	Yes	Keyence connection profile to use
Function Selection	Selection	No	Select Functions (default) reads the functions you list, All Functions reads every read function on the connection, By Labels reads every function whose labels match the labels you pick
Functions	List	With Select Functions	One or more read functions from the selected connection, each with an optional alias that becomes its output key
Execution Mode	Selection	No	How to execute the coalesced requests (parallel or sequential)
Continue on Error	Toggle	No	On by default: a failed read is recorded in the output and the other functions still run. Off: the node fails as soon as any function fails

Output Structure

The node output is the canonical {result, _metadata} envelope: result holds one entry per function read, keyed by the function's output key; _metadata holds the group's accounting.

{
  "result": {
    "Press Count": {
      "value": 1234,
      "success": true,
      "error": "",
      "duration": 11,
      "timestamp": "2026-09-07T08:30:00Z"
    },
    "Line Block": {
      "value": { "count": 2, "values": { "Temperature": 72.5, "Alarm": false }, "quality": "good", "totalDataPoints": 2, "totalReads": 2 },
      "success": true,
      "error": "",
      "duration": 19,
      "timestamp": "2026-09-07T08:30:00Z"
    }
  },
  "_metadata": {
    "connectionId": "conn-123",
    "connectionName": "Press Line KV-8000",
    "total": 2,
    "successful": 2,
    "failed": 0,
    "totalDuration": 83,
    "executionMode": "parallel",
    "originalRequests": 2
  }
}

Each entry under result is one function's read — keyed by the function's alias, else its name, else its id:

Field	Type	Description
result.<alias>.value	any	What the function read — its own result.value when it has one (the decoded value for keyence.read.device, since its result carries value; the whole {count, values, …} object for keyence.read.block), otherwise its whole result. null when the read failed
result.<alias>.success	boolean	true when this function's read succeeded
result.<alias>.error	string	Why the read failed; empty when it succeeded — always present
result.<alias>.duration	number	How long this function's read took, in milliseconds
result.<alias>.timestamp	string	When the read was issued, RFC 3339 UTC

The _metadata object is the group's execution summary:

Field	Type	Description
_metadata.connectionId	string	The connection every function was read on
_metadata.connectionName	string	That connection's display name
_metadata.total	number	How many functions the group ran
_metadata.successful	number	How many read successfully — including the ones onChange then suppressed
_metadata.failed	number	How many failed; successful + failed = total
_metadata.totalDuration	number	Wall-clock time of the whole group, in milliseconds
_metadata.executionMode	string	parallel or sequential
_metadata.originalRequests	number	How many functions were selected to run
_metadata.keyCollisions	string[]	Output keys that two or more functions resolved to — the later read overwrote the earlier under that key. Present only when it happened
_metadata.configWarnings	string[]	Non-fatal problems in the node's config, each saying what was ignored. Present only when there were any
_metadata.outputMode	string	onChange — present only in that mode
_metadata.suppressedCount	number	onChange mode: how many successful reads were unchanged since the last run and left out of result
_metadata.emittedCount	number	onChange mode: how many entries result carries — total − suppressedCount
_metadata.suppressedKeys	string[]	onChange mode: the output keys left out as unchanged. Present only when at least one was
_metadata.reason	string	onChange mode, when every successful read was unchanged: why result is empty — the node buffers instead of waking downstream

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Settings Tab

All Keyence node types share the same Settings tab:

Setting	Type	Default	Description
Description	Text	—	Optional description displayed on the node
Timeout (seconds)	Number	Pipeline default	Maximum time the node may run before timing out
Retry on Timeout	Toggle	Pipeline default	Automatically retry the node if it times out
Retry on Fail	Toggle	Pipeline default	Automatically retry the node if it fails
On Error	Selection	Pipeline default	Error strategy: Pipeline Default (the pipeline's Error Handling setting), Stop Pipeline or Continue Execution

When left at their defaults, these settings inherit from the pipeline-level execution configuration.

Test before wiring

Use Test Function in the function form (on the connection page) to run every Keyence function against the live PLC before wiring it into a pipeline. It catches a wrong address, a hex/decimal mix-up, or a data type the device cannot hold.