Getting started
Start here
Use this page for your first KEYENCE KV Host Link read and write from Node-RED. The examples below use 192.168.250.100:8501.
Prerequisites
| Requirement |
Value |
| Node-RED |
3.0 or newer |
| PLC endpoint |
192.168.250.100:8501 |
| Transport |
TCP unless your PLC setup requires UDP |
Install
| Step |
Action |
| 1 |
Open Node-RED. |
| 2 |
Open Manage palette. |
| 3 |
Choose Install. |
| 4 |
Search for @fa_yoshinobu/node-red-contrib-plc-comm-kvhostlink. |
| 5 |
Install the package and restart Node-RED if prompted. |
Choose profile
The connection node requires an exact canonical PLC profile string. Start with the profile that matches your KV family.
| PLC family |
Profile to select |
| KV-3000 |
keyence:kv-3000 or keyence:kv-3000-xym |
| KV-5000 / KV-5500 |
keyence:kv-5000 or keyence:kv-5000-xym |
| KV-7000 / KV-7300 / KV-7500 |
keyence:kv-7000 or keyence:kv-7000-xym |
| KV-8000 |
keyence:kv-8000 or keyence:kv-8000-xym |
| KV-X500 family |
keyence:kv-x500 or keyence:kv-x500-xym |
| KV-NANO |
keyence:kv-nano or keyence:kv-nano-xym |
Create a connection node
Add or edit a kvhostlink-connection config node.
| Field |
Example value |
Description |
| Name |
KV Host Link TCP |
Display name in the editor. |
| Host |
192.168.250.100 |
IP address or host name for your PLC. |
| Port |
8501 |
Default KEYENCE KV Host Link TCP/UDP port. |
| Transport |
tcp |
Use tcp or udp. |
| Timeout |
3000 |
Response timeout in milliseconds. |
| PLC Profile |
keyence:kv-5000 |
Exact canonical profile value for your PLC. |
Import the basic flow
| Step |
Action |
| 1 |
Open the Node-RED import menu. |
| 2 |
Import examples/flows/kvhostlink-basic-read-write.json. |
| 3 |
Confirm the connection node uses host 192.168.250.100, port 8501, and your canonical PLC profile. |
| 4 |
Deploy. |
| 5 |
Trigger Read DM100. |
| 6 |
Check the debug sidebar for a value. |
Read your first value
For a single manual read, configure a kvhostlink-read node like this:
| Field |
Value |
| Connection |
Your kvhostlink-connection node |
| Source |
str |
| Addresses |
DM100 |
| Output |
Single value when one address |
| Metadata |
Minimal msg.kvhostlink |
| Errors |
Second output |
Successful output is written to msg.payload.
First write
For a single manual write, configure a kvhostlink-write node like this:
| Field |
Value |
| Connection |
Your kvhostlink-connection node |
| Source |
str |
| Static updates |
{"DM100":123} |
| Metadata |
Minimal msg.kvhostlink |
| Errors |
Second output |
Use only a test address that is safe for your machine and PLC program.
Confirm success
| Check |
Expected result |
| Connection status |
The connection node status changes to connected during the request. |
| Read status |
The read node reports 1 item(s). |
| Debug output |
The debug sidebar shows msg.payload. |
| Error output |
The error output stays quiet. |
| Write readback |
The follow-up read shows the value written to your test address. |
If it does not work
| Symptom |
Check |
| Timeout immediately |
Default port is 8501, not 1025. |
| Profile dropdown rejects a value |
Use only the exact values in PLC profiles. |
| First import feels too large |
Import kvhostlink-basic-read-write.json first, not the device-matrix flow. |
| Timer/counter preset write fails |
Timer/counter preset writes only work on KV-8000/7000-series CPU units. |
| Transport fails |
Check that your PLC Host Link setting allows the selected TCP or UDP transport. |
Next pages