Adding a New PLC Connection
This is the procedure for registering a single PLC on a gateway.
Before You Begin
You will need the following information. Having it written down beforehand speeds things up.
| Item | Where to find it |
|---|---|
| PLC IP address | The label on the PLC unit, the network settings screen, or your in-house network administrator |
| PLC communication port | Defaults differ by PLC type. See the Guide by PLC Type in this manual |
| Communication availability | ping <PLC IP> must get a response from the gateway PC |
The PLC must be on the same network segment (VLAN) as the gateway for communication to work. If it is on a different segment, routing or firewall configuration is required.
Procedure
1. Click the [Connections] menu
Click the [Connections] menu at the top of the gateway screen.
2. Click the [Add Connection] button
Click the blue [Add Connection] button above the [Connection List].
3. Select the protocol (PLC type)
On the "Select the PLC or protocol to connect" screen, click the card that matches your PLC.
- If you are unsure which card to choose, see the PLC Type Comparison Table.
- In a test environment without a PLC, you can select the Simulator card.
4. Fill in the registration form
The form layout differs slightly by PLC type. The common fields are as follows.
| Field | Meaning | Recommended value / example |
|---|---|---|
| Connection ID | A unique code that identifies this PLC within the gateway | OPC_LINE1 (letters/digits/underscores; spaces and Korean characters are not recommended) |
| Connection name | The name shown on screen | 1라인 미쓰비시 PLC |
| IP address | The PLC's network address | 192.168.0.60 |
| Port | The PLC's communication port | (differs by PLC type) |
| Site ID | Site code (filled in automatically) | (leave as is) |
| Collection interval (ms) | How many milliseconds between value reads | 1000 (1 second). Use 500 for fast-changing values, 5000 for slow ones |
| Auto start | Whether collection starts automatically when the gateway reboots | 예 recommended for production |
Additional options specific to each PLC type (user / password, series type, etc.) are described in detail on the corresponding page of the Guide by PLC Type.
5. Add tags (which values to read)
In the [Tags] area at the bottom of the same form, add the values to be read, one row at a time.
- [Add] / [Delete] are available per row.
- You can register the PLC with zero tags (they can be added later).
The tag input fields and address notation are covered in detail on the Tag Registration page.
6. Click [Save]
When you click [Save], the following happens automatically.
- The gateway attempts to connect to the PLC.
- It begins reading the registered tags automatically at each collection interval.
- It exports the values to the configured transmission channels, such as the PlantPulse Platform or MQTT.
Please wait a moment. The first values usually arrive within 1 to 3 seconds.
Verification After Registration
When you return to the [Connection List] screen, the registered PLC is displayed. The list refreshes automatically every 5 seconds.
| Color / text shown | Meaning | Next action |
|---|---|---|
| Green "Connected" | OK. Values are coming in | Click the row on the left to check the current value of each tag |
| Red "Connection failed" | Cannot reach the PLC | See Troubleshooting — Cannot Connect |
| Gray "Stopped" | Collection is halted | Click the [Start] button on the right of the row |
Common Follow-up Tasks
| Task | How to do it |
|---|---|
| Edit PLC information | [Edit] button on the left of the row → the form reopens |
| Delete a PLC | [Delete] button on the left of the row. Registered tags are deleted as well (a confirmation dialog appears) |
| Pause collection | [Stop] button on the right of the row |
| Resume collection | [Start] button on the right of the row |
| Add a single tag row | Click the PLC row, then click the [Add Tag] button above the [Tags] table |
Registering Many at Once (Bulk CSV Upload)
If you have dozens to hundreds of tags, entering them one row at a time is tedious. Use the [Bulk CSV Upload] button at the top right of the [Connections] menu to register them all at once from an Excel-format file.
The CSV format and a sample file are described on the upload screen.
Frequently Asked Questions
Q. Can the Connection ID be in Korean?
Please use only letters, digits, and underscores (_). It is an internal system identifier, so Korean characters or spaces may cause problems on other screens or in external integrations.
Q. Can I register a PLC with the same IP twice?
Technically yes. However, the Connection IDs must be different. This is useful when you want to manage different areas of the same PLC separately (for example, the D area and the R area on the same Mitsubishi PLC).
Q. What happens if I set the collection interval too short (e.g., 100 ms)?
The PLC may not keep up, or the gateway may run short on resources. Generally, 500 ms to 1000 ms works well. Set a shorter interval only when you genuinely need fast-changing values.
Q. Where do I enter the PLC password?
Only protocols that use user/password authentication, such as OPC-UA, have a password field in the form. Ordinary PLCs (Modbus / Mitsubishi / Siemens / LS) have no password concept — anyone who knows the IP can connect (take care with in-house network security).