A forgotten SCADA edit password is a credential problem, not damaged project data. Work four supported routes in order: your credential records, a dated project backup, an unprotected copy from the integrator, then vendor support with proof of ownership. Never delete or swap the security file; it holds the site's authorization data and replacing it is unsupported.
The edit password is gone, the operator login still works, and the line keeps running. That combination is good news: the project on disk is intact, and the problem is a lost credential, not damaged data. Edit access comes back through four supported routes, cheapest first: your own credential records, a dated project backup, an unprotected copy from the machine builder or integrator, then the software vendor with proof of ownership. Leave the security file alone, whatever a web search turns up. Several SCADA and HMI packages keep login data in a file on the workstation, which makes that file look like a shortcut; replacing it is the one move that turns a lost password into an unsupported installation.
What the lockout tells you
Write down four things before you touch anything: who can still log in, whether edit mode is reachable, which folder the runtime actually opens, and the modified dates on the project folder and the security file. Ten minutes of inventory picks the cheapest route and leaves the running line untouched.
| What you see | What it points to | First move |
|---|---|---|
| Operator login works, edit mode rejects every password | The edit credential was lost or changed; project data is intact | Records, then the backup and integrator routes |
| Nobody can log in at all | The security data is lost or out of step with the project | Restore the latest dated backup into a test folder, then contact the vendor |
| The same project accepts different logins on two computers | Login data is held on the workstation, not in the project folder | Work from the original machine's records; never copy the file between machines |
| Edits made yesterday are gone today | The runtime is opening a different project or security file than the one you edited | Find the folder the runtime actually opens before changing anything |
Why the security file is the wrong lever
Some SCADA and HMI packages keep login data in a security file on the workstation that runs the software, held apart from the project folder. When yours does, one project accepts different logins on two computers, and a copy of another machine's file looks like a quick fix. Treat the file as the site's authorization record: it says who may alter a running line. Swap it for a file of unknown origin and you hold an installation nobody can account for, credentials nobody can document, and a vendor who will not stand behind the machine afterwards.
Importing the project data into a new project fails the same way from the other end. The new project starts with its own security file and its own users, so the rebuild does not carry the old rights across; the credential is still lost, and weeks of rebuild work buy nothing.
An edit credential is part of the change control that keeps unauthorized hands off a running process, so keep the recovery inside documented channels and the authorization record stays provable.
The four supported routes, in order
- Your own records. Check the handover folder, the commissioning e-mails, the site password manager and the sealed envelope the system owner keeps. Integrators usually sent the edit credential with the handover paperwork, so the paper trail is the cheapest place to look. The modified date on the security file dates the last credential change, and backups dated either side of it tell you what a restore would cost in lost edits.
- A dated project backup. Restoring a project from a backup is a documented function in mainstream SCADA packages, and your vendor's manual for the installed version describes the restore step. Restore into a clean test folder, compare the restored copy with the running project, and only then decide. The cost is the gap between the backup date and the last change date, counted in days of edits you would lose. If the project runs on an HMI panel instead of a PC node, take the panel backup first, following the safe sequence for backing up and restoring an HMI panel project. And when a restore will not come back up, the fix for an HMI project restore that fails after reboot is usually in the restore path, not the project.
- The machine builder or integrator. The firm that built the project keeps the source and, in most cases, the credentials. Ask for the current edit credential or an unprotected copy of the source project, and be ready to show you own the system. Who owns the program depends on the contract you signed; how PLC program ownership splits between the OEM and the integrator covers the two patterns and what each side can ask for.
- Vendor support. Contact whoever licenses your copy with the software name, version, license or serial number, purchase records and the project name. Vendors treat a lost edit credential as an ownership case and apply the documented reset for your version. Ask what the reset requires before you send anything, and record the answer in the handover file.
Scenario: a line no one can edit
A packing line was commissioned in March 2019, and the integrator set the SCADA edit password at handover. The integrator closed in 2023. Today the operator login works, edit mode refuses every password anyone remembers, and maintenance wants to change a reject-counter text label.
Route 1, records: the handover folder holds the license serial and the software version, but no credential. Route 3 is closed with the integrator gone. Route 2: the most recent dated backup is from 12 February 2024, and the project files were last modified on 18 March 2024, the day the last tuning change went in. 2024 is a leap year, so 12 February to 18 March is 17 days left in February plus 18 days in March, 35 days of edits a restore would throw away. The plant rejects route 2.
Route 4: the plant sends the vendor the license serial, the purchase records and the version. The vendor confirms ownership and applies its documented reset. Edit access comes back with all 35 days of changes intact, the label is edited the same afternoon, and the runtime never stopped, because the operator login had stayed valid the whole time.
Before the project goes back to service
- Log in with the restored credential and open edit mode.
- Make one small reversible change, a text label, and save it.
- Close the runtime, reopen it, log in again, and confirm that edit mode still opens and the label kept its new text.
- Run the cycle once more before the next production change.
- Put the working credential where the system owner keeps credentials, and hold the pre-recovery backup until the first production change has been validated.
Keep the next lockout from happening
- Record every edit credential in the site's password manager or a sealed envelope held by the system owner. Control projects outlive their authors; the hardware support cycles behind a line commonly run 15 to 20 years.
- Give each administrator a separate edit credential where the software allows it, and keep each credential's scope narrow. A parameter edit password that opens every screen at once turns one leaked login into a plant-wide problem.
- Take a dated backup after every change and keep at least three generations off the workstation. Refresh the set on a fixed routine, the way keeping a master copy of an HMI project sets out.
- Make 12 characters the minimum for an edit credential. The NIST digital identity guidelines put the floor for a stored password at 8 characters, and a credential that can change a running line deserves the extra margin.
- Keep a one-page handover sheet with the software name and version, the license serial, the support contact and the backup location, and refresh it when someone leaves.
Recommendation: If the operator login still works, inventory what works and which backups are dated, then work the four routes in order and leave the security file untouched. If nobody can log in at all, restore the latest dated backup into a test folder and contact the vendor the same day with the license serial and purchase records.
Questions
Can I import the project data into a new project and skip the password?
No. A new project starts with its own security file and its own users, so importing the data builds a fresh project; the old credential stays lost. Rebuilding from the source is a legitimate fallback when you hold it: screens, tags, alarms and scripts are recreated from the P&ID, the I/O list and the PLC program, which is weeks of work for a full line. Spend a day on the four supported routes first.
What proof of ownership does a vendor ask for?
Expect to provide the software name and version, the license or serial number and the original purchase record. Some vendors want the request to come from the contact registered on the license. Send the serial from the handover sheet even if the license has expired; the support team will tell you what a reset for your version requires before any work starts.
Where does the login data live?
In several SCADA and HMI packages it lives in a security file on the workstation that runs the software, separate from the project folder. That is why a project moved to a new computer can accept different logins. Your vendor's security documentation names the file for your version; include it in the backup set and record it in the handover sheet so a rebuild or a new workstation does not strand the project.
Is the running line safe while the password is recovered?
If the operator login still works, the runtime keeps running and the process data is untouched; the lockout blocks edits, not operation. Leave the runtime as it is, work the recovery routes alongside it, and restart nothing and reinstall nothing until a dated backup exists. If nobody can log in at all, treat the security data as suspect and restore from backup before trusting the running copy.
Planning information, not legal or engineering advice. Rules differ by place: check codes and permits with your local authority and your licensed trades.