After a link loss the panel first posts PLC-001 PLC Communication Timeout, then changes to PLC-015 with your communication setup's name and No device found. The 015 is the panel's error number, not a PLC or node number. Read the setup name, then repair the path: cable, LINK LEDs, network settings.
A panel that posts PLC-015 No device found is not talking to a fifteenth PLC. The digits after PLC- are the panel's own error number, and the text beside them names one of your configured communication setups. On the panel in this case, a 10-inch HMI on firmware v2.42 driving a DL06 PLC through an ECOM-100 Ethernet card, pulling the Ethernet crossover cable brought up PLC-001 PLC Communication Timeout first and PLC-015 DL06_1 No device found within about half a minute. DL06_1 was the name of the only communication setup in Panel Manager. Nothing new joined the network; the only thing lost was the link. Read the setup name in the message, then repair the path in this order: cable, LINK LEDs, network settings.
What the number in PLC-015 actually is
The PLC- prefix opens an error code and the digits finish it. PLC-001 carries the text PLC Communication Timeout. PLC-015 carries No device found, and the panel appends the name of the communication setup it was trying to reach. The panel's help file lists these codes, and the number is the entry in that list, not an address on the wire. On the case panel the full alarm read PLC-015: DL06_1 No device found, and DL06_1 was the name assigned to the communication setup in Panel Manager. The message therefore makes one statement: the setup named DL06_1 found no device at the far end.
That reading settles the next move. The code does not ask for a second PLC entry, a new node address or a renamed setup. It asks for the link named in the text to carry data again. If your project genuinely talks to several PLCs, the setup name in the alarm is what identifies the failed one; tell which PLC lost communication on a multi-PLC HMI panel covers that case. For the full repair walk-through on this exact panel-to-DL06 pairing, a knowledge base page on resolving the PLC-015 device not found error follows the same order of checks.
Symptoms and what each points to
| What you see | What it points to | First move |
|---|---|---|
| PLC-001 PLC Communication Timeout starting when the cable comes out | The panel lost its path mid-conversation; the expected response to a deliberate disconnect | Restore the link |
| The timeout text reposting every few seconds | The panel is retrying the same configured setup | Let it retry; leave the project alone |
| PLC-015 with your setup name and No device found | The same lost-link condition, one stage later; 015 is the error number | Repair the physical path |
| PLC-015 or PLC-001 with the cable seated and the LEDs steady | The cable pull no longer explains the alarm; the fault sits in settings or in the device | Compare network values, confirm the PLC is powered |
The alarms post as text at the top-left edge of the screen. A timeout that comes and goes while the cable stays untouched is a different pattern, covered in why an HMI shows an intermittent PLC communication timeout.
Example: timing PLC-015 after a cable pull on a DL06 link
Inputs, and where each comes from:
- PLC-001 display time: about 5 seconds at the top-left edge of the screen, from the case panel's behavior.
- Gap before the repost: about 1 to 2 seconds, same observation.
- Timeout postings before the text changes to PLC-015: about 3, same observation.
- Setup name in the new text: DL06_1, read from the project's Panel Manager.
- Hardware: a 10-inch HMI on firmware v2.42, a DL06 PLC with an ECOM-100 Ethernet card, an Ethernet crossover cable.
The rule in words: seconds from link loss to the PLC-015 text equals the number of timeout postings times one full cycle, where a cycle is the display time plus the gap.
Arithmetic: shortest cycle 5 + 1 = 6 seconds, so 3 × 6 = 18 seconds. Longest cycle 5 + 2 = 7 seconds, so 3 × 7 = 21 seconds. The change of text lands between 18 and 21 seconds after the pull, call it about 20 seconds.
Result: on this panel, PLC-015 DL06_1 No device found arriving about 20 seconds after a link loss is the normal end of the timeout sequence.
Decision: if PLC-015 appears within about half a minute of a known link loss and names a setup you configured, treat it as the standard lost-device message and repair the path. If it appears with the cable in place and the LINK LEDs steady, the link loss does not explain it, so move to the settings checks below. The 5, the 1 to 2 and the 3 are one panel's observation; trust the order of the sequence, and treat the seconds as approximate.
Checks, in order
- Reseat the cable at both ends and substitute a known-good Ethernet cable if one is on the bench. The case link is a crossover cable running straight from the panel to the ECOM-100 card; keep that same topology while testing, so the result says something about the original link.
- Read the link LEDs. The Ethernet module's documentation gives the LED meaning: the green LINK LED on steady means the module is correctly connected to an active device on the network and is receiving 5 VDC. A dark or flickering LED points at the cable, a connector, a port or the module, and the project can stay closed. knowledge base page on resolving the PLC-015 device not found error includes this LED check.
- With the physical link confirmed, read the IP settings from the panel project and from the PLC's Ethernet card and compare them value by value. Read them from the equipment; never guess an address.
- Confirm the PLC is powered and the project still targets the intended setup, DL06_1 in this case.
- Change one mismatch at a time and repeat the same live-data check after each change, so the fix that worked is the one you know.
If the alarm's first appearance followed a power cut rather than a cable pull, the supply and the boot order come first; PLC COM timeout after power-up: check supply and boot order walks that sequence.
The fix, and the decision for each case
The fix is to restore the path and confirm live data. It is never to type the code's digits into the project as an address. With the cable seated and the LINK LEDs steady, the panel resumes exchanging data with the DL06, the alarm clears and the values on screen move again. If live values stay frozen after a clean reconnect, the fault sits in settings or in the device, and the checks above take you there one step at a time.
Decisions by case:
- The alarm appears only while the link is deliberately open: correct behavior, close the link and continue.
- PLC-015 appears about 20 seconds after a real link loss and names your setup: the standard sequence, so repair the cable, the connectors and the LINK LEDs first.
- The alarm persists with a good link and matching settings: check the PLC's power supply and its Ethernet card next; the panel side is then cleared.
- The temptation is to silence the alarm: leave it enabled. During a link loss every value on the panel stops updating, and an operator acting on a stale number can make a wrong move on the machine. The alarm is the notice that the screen has stopped matching the plant.
Recommendation: Treat PLC-015 as the panel's error number for a lost device. Read the setup name in the text first; when it matches a setup you configured, spend the effort on the physical path, the LINK LEDs and the network values, in that order, and keep the communication alarm enabled while you work.
Questions
Does PLC-015 mean the panel found another PLC on the network?
No. The 015 is the panel's error number for the no-device condition, from the same list that gives 001 for a communication timeout. The text beside the number names one of the communication setups configured in the project. The panel talks to the setups you define, and this message reports that the named setup found nothing at the far end. Adding a second PLC entry or changing node addresses because of the digits sends the work the wrong way; read the setup name, then check the physical link.
Why does the alarm name a communication setup I do not recognize?
The name after the error text comes from the project loaded on the panel, not from the network. If the name in the alarm is not one you set up, the panel is probably running a project other than the one you have open. Compare the communication setups in the project file against the alarm text and confirm which project was last sent to the panel, before changing any address.
How do you confirm communication is restored after the fix?
Watch three things at once: the alarm text at the top-left edge of the screen stops reposting, a live value tied to the PLC changes when the machine state changes, and the LINK LED stays steady green. If the alarm cleared but the numbers stay frozen, the panel is showing its last update, so the path or the settings still need work. Confirm with a value you can force at the PLC, so the check exercises both directions of the link.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.