When several Totalflow devices appear behind one IP address, the deciding question is whether that address terminates at each device, at a gateway, or at a master device. Entering the shared IP in PCCU identifies a network endpoint; it does not, by itself, identify one station behind that endpoint.
Check what the shared IP represents
Before entering an address in PCCU, map the communication path from the SCADA server to the intended Totalflow. Confirm whether the devices are each Ethernet-connected, linked over a serial network to a master, or reachable through a cellular modem or other gateway. A shared address can describe a gateway through which multiple stations communicate; it does not prove that the individual Totalflows share a usable Ethernet identity.
- Prerequisite: Obtain the network diagram or inspect the field wiring and modem configuration. Record the server-side destination IP, the device or station address for each Totalflow, and any master/client relationship. Gate: Continue only when you can name the physical or logical device that owns the IP connection.
- Read the IP configuration: Compare the IP address assigned to each device with the address PCCU is expected to contact. If each device has its own IP, record the target device’s IP. If multiple stations are reached through one IP, identify the gateway or master that receives the connection. Gate: If ownership or routing is unclear, resolve it before testing a station address.
The examples in the reported setup include one network address, 166.142.65.9, associated with station addresses 456120 through 456129. Another example uses cellular modem address 10.1.100.100 and station number 799. These illustrate the distinction between an IP endpoint and a station identifier; they are not a recommended addressing scheme for another installation.
Classify the communication path
Use the path, not the SCADA display convention, to decide what PCCU needs. A SCADA application may present a station-address field while PCCU may require a direct IP endpoint, a connection through a master, or another supported communication path. Those are different connection models.
| Observed arrangement | What the IP identifies | Next check |
|---|---|---|
| Each Totalflow has its own Ethernet address | The individual device endpoint | Connect to the intended device’s IP and verify the PC network path. |
| Several addresses are represented by a modem or gateway | The gateway endpoint, not necessarily a specific Totalflow | Determine whether the gateway routes or maps connections by station, port, or another configured method. |
| Devices are serially linked to a master | Potentially the master endpoint | Confirm the master/slave arrangement and whether PCCU can select a downstream station on that path. |
| Same IP is claimed for multiple independently Ethernet-connected devices | Address conflict or an undocumented network design until proven otherwise | Check actual IP assignments and network configuration before attempting a PCCU station selection. |
For a normal IP connection, routing delivers packets to an IP endpoint. Selecting one downstream device requires another mechanism, such as a gateway mapping, a master’s protocol-level station selection, or a distinct endpoint/port. A station number in a SCADA database does not automatically become a PCCU selector.
Verify the target IP and PC network path
When each Totalflow has a distinct IP, follow the direct-IP branch. When the IP belongs to a shared modem or master, use this check only to confirm reachability to that gateway; a successful IP connection does not establish which downstream station PCCU will address.
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Prerequisite: Have the intended target IP and the SCADA server’s network settings. In PCCU, open
Setup > TCP/IPand enter the exact IP of the intended endpoint. Gate: Confirm that the entered address matches the network plan before connecting. - Read the PC addressing: Compare the server’s IP scheme and subnet with the destination network. If they are on the same subnet, confirm the address and subnet mask are correct. If they are on different networks, confirm that a configured route or gateway provides the path; changing the PC’s scheme is appropriate only when authorized and consistent with the network plan. Gate: Proceed when the server has a valid route to the endpoint.
- Attempt the connection: Connect to the endpoint in PCCU. Record whether the connection succeeds or fails. Gate: A successful connection advances to station-selection verification; a failure calls for IP, subnet, route, and endpoint checks before changing station-address values.
Determine whether PCCU can select a downstream station
After the endpoint is reachable, inspect the PCCU connection workflow and the device communication configuration for an explicit station, device, or address field. Use the field’s documented purpose: a station address must be part of the communication path that carries the request to the downstream Totalflow. Do not infer that a similarly named SCADA field is available or interpreted the same way in PCCU.
- Prerequisite: Know the target station address and the gateway/master path. Open the relevant PCCU communication setup and look for an explicit station-selection field or supported connection mode. Gate: If the field exists, confirm its scope and allowed format from the PCCU/device documentation before entering the address.
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Enter the target station only in a confirmed field: For the example range
456120–456129, the fifth address is456124when counting456120as the first. Gate: Confirm that the field accepts the address and that the endpoint is the master or gateway serving that station. - If no selector appears: Do not treat the IP field as a combined IP-and-station field unless PCCU documentation for the installed version explicitly says so. Determine whether PCCU must connect to a master, use a separate communication mode, or reach each device at a unique IP. Gate: Do not proceed with an unverified syntax.
Evaluate the proposed slash-address format
A suggested format in the discussion was an IP followed by a slash and station number, such as 10.1.100.100/799. Treat this as an unverified test idea, not as an established PCCU syntax. The fact that a SCADA system uses a modem IP plus station number does not establish that PCCU parses a slash suffix or sends that number in the required protocol field.
Use the format only if PCCU documentation or an explicit PCCU input field confirms it. If a controlled test is authorized, record the PCCU version, exact entry, target endpoint, and station selected; then verify that PCCU reports and communicates with the intended device rather than merely opening a connection to the modem. If the entry is rejected or PCCU connects to the wrong endpoint, remove it and return to the supported configuration path. Do not change the network address plan to compensate for an unsupported address format.
Use symptoms to choose the next diagnostic
| Symptom | Likely branch | Next diagnostic |
|---|---|---|
| PCCU cannot connect to the entered IP | IP reachability or route problem | Recheck the destination, PC subnet, and gateway/route. Confirm the endpoint is online before investigating station selection. |
| PCCU connects, but the intended station is not identified | Shared endpoint without confirmed downstream selection | Check for an explicit PCCU station selector and confirm whether the endpoint is a master or gateway that serves that station. |
| SCADA can read a station while PCCU cannot select it | The applications may use different connection workflows | Compare the SCADA endpoint and station configuration with PCCU’s documented fields; do not assume the SCADA station setting transfers to PCCU. |
| Multiple devices appear to have the same Ethernet IP | Possible gateway mapping, serial/master arrangement, or duplicate IP configuration | Inspect the wiring and device IP settings to distinguish these cases before connecting. |
| The slash-address entry is rejected or reaches the wrong device | Unsupported or incorrectly interpreted syntax | Remove the suffix and use a documented station-selection field or supported network path. |
Commission the resolving connection path
Once the topology and supported PCCU workflow are confirmed, use the applicable branch below. Keep the endpoint address and station identifier as separate recorded values unless the installed PCCU documentation explicitly defines a combined field.
- Prerequisite: Confirm whether the target has a unique IP or sits behind a master/gateway, and obtain the supported PCCU settings for that path. Gate: Do not start commissioning while the endpoint owner or station-selection method remains unclear.
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For a unique-IP device: Enter that device’s exact IP in
Setup > TCP/IP, confirm the SCADA server’s subnet or route, and connect. Gate: Continue only after PCCU establishes communication with the endpoint. - For a downstream station: Connect to the confirmed master/gateway endpoint and enter the station address only in the documented selector. If PCCU has no such field, use a different supported access path rather than guessing a suffix. Gate: Continue only after PCCU indicates the intended station.
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Verify device identity: Read a device-specific identification value or known live data point and compare it with the target station record. For the numbered example, verify that the selected station is
456124, not merely that a session opened to166.142.65.9. Gate: Treat the connection as commissioned only after the returned identity/data matches the intended Totalflow.
Frequently asked questions
Can I enter a Totalflow station address after the IP in PCCU?
Use a combined IP/station format only when PCCU documentation or an explicit field confirms it. The proposed form 10.1.100.100/799 is not established as PCCU syntax; otherwise select the station through the documented master/gateway workflow.
Does entering the IP address select one of several Totalflows?
No. The IP identifies the network endpoint. Selecting a downstream device requires a supported station selector, gateway mapping, master path, or unique IP for that device.
Can PCCU reach the fifth device at 166.142.65.9?
The example station range is 456120 through 456129; counting 456120 first makes the fifth station 456124. PCCU must support selecting that station through the endpoint at 166.142.65.9.
Does a successful PCCU connection prove I selected the right station?
No. It proves that PCCU reached an endpoint, not necessarily the intended downstream device. Read a device-specific identity value or known data point and compare it with the target station record.
Can changing the SCADA server subnet fix a failed PCCU connection?
Only when the network plan requires a different PC scheme and the change is authorized. First compare the PC IP/subnet with the destination and confirm the required route or gateway; then retry PCCU and verify the target device identity.