Robotics in Manufacturing

Controller & setup

Performing a Controlled Start

For a technician who needs the controlled start menu to change protected (R0) system variables, read or restore system files, and reach maintenance and memory settings that normal operation locks out. Boot it by holding [PREV] and [NEXT] at power-on and selecting 3 Controlled start, then return to production with a cold start. The simple controlled start system cannot move the robot, so verify FROM space and back up first.

Intermediate~20 min20 steps
  1. Step 1.

    Back up before you change anything

    Make a current backup of programs and system files. Controlled start exposes system variables and maintenance screens that can alter motion parameters, so a known-good backup lets you restore if a change goes wrong.

  2. Step 2.

    Confirm at least 600 KB of free FROM

    The controller will not offer controlled start when free FROM drops below 600 KB. Check free space in the memory status menu (select MENU, 0 Next, 4 Status, Memory), and if it is low, remove unnecessary data from the FR: or FRA: device first.

    Caution: The configuration menu hides the controlled start option when the rest of FROM is less than 600 KB.

  3. Step 3.

    Stop production and clear the cell

    Confirm no program is running and that it is safe to power the controller down. Announce the shutdown and keep others clear of the robot.

  4. Step 4.

    Power off the controller

    Shut the controller down using the normal procedure, then set the main power breaker to OFF.

  5. Step 5.

    Boot into the configuration menu

    Hold the [PREV] and [NEXT] keys on the teach pendant while setting the controller power breaker to ON. Keep both keys held until the CONFIGURATION MENU appears.

  6. Step 6.

    Select "3 Controlled start"

    From the menu (1 Hot start, 2 Cold start, 3 Controlled start, 4 Maintenance), choose 3. The controlled start menu loads as a simple system and opens the Tool Setup screen.

    Caution: The controlled start menu cannot operate the robot; jogging and program execution are unavailable in this mode.

  7. Step 7.

    Open the screen you need from [MENU]

    Press [MENU] to reach the controlled start screens: Tool Setup, Software Version, Variables, File, Alarm history, Port Init, Memory, Maintenance, Max. number setting, Password, and Host Communication. Only the screens in this simple system are available here.

  8. Step 8.

    Change a protected system variable, if that is the task

    Press [MENU] and select "4 Variables". At controlled start you can edit variables that are read-only (R0) during normal operation, so change only the specific variable your task calls for.

  9. Step 9.

    Read a system file or restore a backup, if that is the task

    Press [MENU] and select "5 File". At controlled start, F4 shows [RESTORE] and system files can be read that a normal file screen will not load; pressing F4 reads files, and "all of above" reads all files at once.

    Caution: Restoring overwrites the controller's current programs and settings with the backup contents.

  10. Step 10.

    Switch F4 between RESTORE and BACKUP if needed

    On the controlled start file screen, F4 defaults to [RESTORE]. To back up instead, press [FCTN] and select RESTORE/BACKUP to toggle F4.

  11. Step 11.

    Load files over a communication link, if that is the task

    To load files by communication at controlled start, set up the serial port first. Use the Port Init screen and the Host Communication setting screen to configure the port before loading from the File screen.

  12. Step 12.

    Release a password restriction if a screen is locked

    When settings are restricted by password level, the Password setting screen releases the restriction. Enter the password there to unlock the restricted setting for the session.

  13. Step 13.

    Adjust a memory allocation limit, if that is the task

    The Max. number setting screen changes how many registers, macros, and user alarms the controller reserves. Some counts, such as the payload schedule count set through $PLST_SCHNUM, need the variable set, then a power cycle and a second controlled start before they apply.

  14. Step 14.

    Leave Maintenance alone unless reconfiguring the robot

    The Maintenance screen changes mount type, payload mode, and extended axis. Running Robot Maintenance returns all motion parameters to default, so path, cycle time, and joint axis limits can change even if you touched nothing.

    Caution: Enter Maintenance only when you intend to reconfigure the robot, and back up first.

  15. Step 15.

    Exit with a cold start

    When your task is done, press [FCTN] and select "1 START (COLD)". The controller performs a cold start and comes up ready to operate.

  16. Step 16.

    Verify normal operation resumes

    Confirm the robot boots to the normal UTILITIES screen and programs are accessible. Check that the setting you changed took effect and that mastering and frames read as expected.

  17. Step 17.

    What can go wrong: "3 Controlled start" will not select

    Free FROM is below 600 KB, so the configuration menu blocks the option. Check free FROM in the memory status menu and clear unnecessary files from the FR: or FRA: device, then reboot into the configuration menu.

  18. Step 18.

    What can go wrong: the robot will not jog in controlled start

    This is expected behavior. The controlled start menu is a simple system that cannot move the robot, so finish your setup, then cold start with [FCTN] and "1 START (COLD)" to operate.

  19. Step 19.

    What can go wrong: a variable change seems ignored

    Some system variables apply only after a restart. Set the variable, power cycle the controller, enter controlled start a second time, then cold start so the new value takes effect.

  20. Step 20.

    What can go wrong: confusing controlled start with initial start

    Initial start (INIT start from the BOOT MONITOR, reached by holding F1 and F5 at power-on) erases every program, all settings, and the factory mastering data. Controlled start changes none of that on its own, so if a screen offers to reset or initialize, stop and confirm you are not triggering an initial start.

    Caution: An accidental initial start erases mastering; correct the cause, restore from backup, and route mastering recovery to a qualified technician.

Common questions

How long does Performing a Controlled Start take?
Performing a Controlled Start is rated Intermediate and takes about 20 minutes across 20 steps.
What tools do I need?
You will need Teach pendant, Access to the controller's main power breaker, Storage device (USB memory or memory card) if reading or restoring files.
What should I do before starting?
Robot can be safely taken offline and the controller power cycled. A current backup of programs and system files before changing variables or restoring. At least 600 KB of free FROM so the controller will offer controlled start.
What is the first step?
Back up before you change anything. Make a current backup of programs and system files. Controlled start exposes system variables and maintenance screens that can alter motion parameters, so a known-good backup lets you restore if a change goes wrong.

Attribution

Procedure steps on this page are checked against the site's editorial safety rules and manufacturer-manual sourcing standards.

Last reviewed: 2026-07-21.

Edited by Mike Ramsey / Reliable Media.Editorial process