Edge Category — Gateway-Specific Nodes

The following nodes are available in the 엣지 category of the palette.

2026.05+ Node Package

node-red-contrib-plantpulse-edge resides at node/conf/plantpulse-edge-nodes/ inside the image, and the entrypoint creates an absolute-path symlink to node_modules/node-red-contrib-plantpulse-edge on every boot. 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 (7 total). Automatically updated on image upgrade.

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

Retrieves a single tag value 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`). Leave blank to specify dynamically via `msg.tagId`
Fresh	When checked, reads directly from the PLC (bypasses cache). Equivalent to `?fresh=true`. Normally leave off (PLC load)
Host / Port	Gateway address (default `127.0.0.1:80` — leave as is on the same machine)

Input (optional):

msg.tagId — dynamically overrides the node's Tag ID setting (reuse one node for multiple tags)
msg.fresh — boolean, dynamically specifies 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.tagId = "TAG_TEST_00042"   // 실제 사용된 ID

Dynamic Tag ID Pattern — Recommended

Leaving the node's Tag ID blank and populating msg.tagId = "TAG_..." with a change node is the most flexible approach. The same read node can then be reused for multiple tags.

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

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

Field	Description
Name	(Optional)
Tag ID	Tag to write. Can be specified dynamically via `msg.tagId`
Value	Fixed value (optional). Priority order: `msg.value` → `msg.payload` → node Value
Host / Port	Gateway address

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 are all supported. Depending on PLC firmware/patch level, EIP may reject writes for certain data types — verify on a simulator before applying to live equipment.

Writes Are Dangerous

Writing a value to a live PLC can set equipment in motion. Verify thoroughly with a test tag or a simulator OPC before applying to a live equipment tag. Use write permissions only on tags agreed upon with the operations team.

3. Next Steps

MQTT Nodes in Detail — integration with external SCADA / cloud IoT
IIoT Example Collection — real-world patterns combining read/write

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