Edge Exclusive Nodes

The following nodes are available in the PlantPulse Edge category of the palette.

2026.05+ Node Package

node-red-contrib-plantpulse-edge is located within the image node/conf/plantpulse-edge-nodes/, and the entrypoint creates an absolute path symlink during every boot node_modules/node-red-contrib-plantpulse-edge. Provided nodes: pp-tag-value-read / pp-tag-value-write / pp-tag-values-read / pp-tag-list / pp-opc-get / pp-opc-start / pp-opc-stop (Total 7). Automatically updated during image upgrade.

1. Read Tag Value (`pp-tag-read`)

Retrieves the value of a single tag from the gateway. Internally calls GET /api/v1/tag/{tagId}/value.

Field	Description
Name	(Optional) Node name
Tag ID	Tag to read (e.g., `TAG_TEST_00042`). If left blank, dynamically specified via `msg.tag_id`
Fresh	If checked, reads directly from PLC (bypasses cache). Same as `?fresh=true`. Keep off during normal operation to reduce PLC load
Host / Port	Gateway address (Default `127.0.0.1:80` — leave as is if on the same machine)
API Key	Value sent as `X-API-Key` when REST API authentication (`edge.rest.api.auth`) is enabled (`edge.rest.api.key`). Can be overwritten by `msg.api_key`

Inputs (Optional):

msg.tag_id — Dynamically overwrite the Tag ID in node settings (allows one node to be reused for multiple tags)
msg.fresh — Boolean, dynamically specify cache bypass

Output:

msg.payload = {
  tag_id: "TAG_TEST_00042",
  value:  "1234",
  value_time: "2026-05-08 03:01:19.001",
  value_read_status: "OK",
  ...
}
msg.statusCode = 200
msg.tag_id = "TAG_TEST_00042"   // 실제 사용된 ID

Dynamic Tag ID Pattern — Recommended

The most flexible method is to leave the Tag ID in the node settings blank and fill msg.tag_id = "TAG_..." using the change node. This allows the same Read node to be reused across multiple tags.

2. Write Tag Value (`pp-tag-write`)

Writes a value to a single tag in the gateway. Internally uses POST /api/v1/tag/{tagId}/value.

Field	Description
Name	(Optional)
Tag ID	Tag to write. Can be dynamically specified via `msg.tag_id`
Value	Fixed value (Optional). Priority order: `msg.value` → `msg.payload` → Node Value
Host / Port	Gateway address
API Key	Same as Read node — `edge.rest.api.key` value

Output:

msg.payload = {
  result: "SUCCESS",         // 또는 "ERROR"
  opc_id: "OPC_LS_TEST",
  plc_address: "D1000",
  value: "9999",             // 사용자가 보낸 값
  actual_read: "9999",       // 드라이버가 write 후 즉시 read 한 결과
  msg: ""
}
msg.statusCode = 200

Supported Protocols: HTTP / OPC-UA / Modbus TCP / MELSEC / S7 / LS XGT(XGI/XBC/XBM) / AB EtherNet/IP. For EtherNet/IP, write requests for certain data types may be rejected depending on PLC firmware/patches; verify in a simulator before applying to actual equipment.

Write Operations are Hazardous

Writing values to an actual PLC can cause equipment to move. Thoroughly verify using test tags or a simulator OPC before applying to actual equipment tags. Only use write permissions for tags agreed upon with the operations team.

3. Next Steps

MQTT Node Details — Integration with external SCADA / Cloud IoT
IIoT Example Collection — Practical patterns combining read/write operations

1. Read Tag Value (pp-tag-read)​

2. Write Tag Value (pp-tag-write)​

3. Next Steps​

1. Read Tag Value (`pp-tag-read`)

2. Write Tag Value (`pp-tag-write`)

3. Next Steps