Mazak: Running a Program at the Control

Everything else in the Mazak section is about writing programs. This one is about getting a program that already exists to run, on a control whose own manual for the job is literally titled Preparation for Automatic Operation — because on a Mazak most of the work of starting a program happens before you touch the start button. The control is generous about it: Mazak’s own summary is that automatic operation “becomes possible just by selecting the program to be executed and then starting it, provided that errors are not present in the program or data.” The whole difficulty lives inside that proviso.

The Short Version

Five stages, in this order. Each one has its own alarm if you skip it, and those alarms are collected at the bottom of this page.

• Machine ready. Tools mounted and their data set, fixture in place, program zero point set. Mazak treats these as prerequisites, not as part of starting.
• Select the mode. Memory operation for a program that lives in the NC. Tape operation and MDI are different things.
• Select the program. Call the POSITION display, tap [WORK No.], pick the work number. Mazak calls this a work number search.
• Select the execution conditions. Single block, optional stop, dry run, machine lock — these are menu items you choose before starting, and can also toggle during a run.
• Press the cycle start button. It lights while automatic operation is in progress and goes out when the program ends.

What Generalizes and What Does Not

This page is built from two machine-specific manual sets: a VARIAXIS C-600 running MAZATROL SmoothAi, and an HCN-5000 running MAZATROL SmoothG. The control-level behavior below — operating modes, work number search, the restart functions, the execution-conditions menu, the alarm numbers — is documented in Mazak’s shared NC-unit books and is common across Smooth machines. The machine level is not. Panel layout, which physical keys exist, which functions are fitted as options, and behavior tied to turrets, pallet changers or a lower turret vary by machine and by how it was specified. Where a paragraph below says “the key” or “the switch,” find its equivalent on your own machine’s operating manual rather than assuming the position.

Two consequences worth stating plainly. First, some functions carry Mazak’s own caveat — Smooth restart, for example, “may not be available depending upon the specifications of the machine.” Second, nothing here is claimed for the pre-Smooth generations. MATRIX, FUSION 640 and the older T/M-Plus controls are outside the manual set this page is written from, and we are not covering them; see the Mazak Control & Machine Family Guide for the lineage.

Which Mode Actually Runs a Program

A Smooth control separates automatic operation into three modes, selected by their own keys on the operating panel, plus the manual modes that stop automatic operation the moment you select one.

Mode	What it is for	Runs a stored program?
Automatic modes — the execution-conditions menu applies to all three
Memory operation	Executes a program registered in the NC memory. This is the normal production mode.	Yes
Tape operation	Loads and executes an EIA/ISO program held on external media at the same time — the program is streamed rather than resident.	EIA/ISO only, from outside
MDI	Executes data the operator types that corresponds to an EIA/ISO program. Used to check a machine action, do setup work, or run a few blocks.	What you type, not a stored program
Manual modes — selecting one stops automatic operation immediately
The manual mode keys	Moving the machine by hand, setup, measurement. Which manual modes your panel offers is machine-dependent — what is not machine-dependent is that pressing one during a program stops the spindle and axes at once.	No

The Mazak-specific reality on top of that: the control runs two kinds of program out of the same memory. On the PROGRAM FILE display each entry’s WORK No. column carries a type flag — M for a MAZATROL conversational program, E for an EIA/ISO G-code program. You select and start both the same way, through the same work number search and the same cycle start button. Where they diverge is in what the control can do with them once running, and that divergence is the source of most of the surprises further down this page. Block Skip works only on EIA/ISO programs. Single-process mode works only on MAZATROL programs. The two restart functions are separate implementations with separate rules. And you cannot restart from inside a subprogram of the other type: restart from a subprogram is limited to the case where main and sub are both MAZATROL, or both EIA/ISO.

Selecting the Program: The Work Number Search

Mazak does not talk about opening a file. A program is identified by its work number, and choosing one for execution is a work number search. In memory operation mode:

Press the memory operation key
Call the POSITION display
Tap [WORK No.]              the WORK No. SELECT window opens
Enter the work number       or pick it from the list
Tap [OK]                    that program is now the foreground program

Two things about work numbers catch people out. The first is that a program also has a name — up to 48 alphanumeric characters, set with [NAME INPUT] on the PROGRAM FILE display — and the name is purely for identification. Mazak is explicit: “even without a program name, however, program execution itself is not affected.” The name is not what you select; the work number is. The second is that the program you selected becomes the foreground program, and quietly replacing it later has consequences for any restart you were planning (see below).

Select a work number that was never registered and you get PROGRAM No. NOT FOUND (405) — the same message text, at a different number (844), also appears at run time when an EIA/ISO program calls a subprogram that is not registered. Try to change the work number at the wrong moment and the control refuses in two distinct ways: pressing cycle start while the work number is being changed raises ILLEGAL CYCLE START (144, sub-code 0x124), and changing the work number after an EIA/ISO restart search has completed raises RESTART SEARCH FINISHED (449). The fix for the second one is always the same: press reset first.

Preparation for Automatic Operation

This is the content Mazak thought was important enough to name a manual after, and it is the part most operators skip past. The chapter assumes tooling and machine adjustment are already done, then lays out the work in three groups before automatic operation begins.

Stage	What Mazak lists	Where you do it
Tool data setting	Coordinates data setting for the tools; registration of the tool shape and the conditions of its usage	TOOL DATA display (register the magazine-mounted tools, set shape and management data, measure tool lengths); TOOL FILE display for milling tool geometry; TOOL OFFSET display for the radius and position compensation used by EIA/ISO programs
Program creation	Program data setting; machining shape check; tool path check; confirmation of the process layout	PROGRAM display, SHAPE CHECK, TOOL PATH CHECK, PROGRAM LAYOUT
Data setting for set-up job	Setting of the program zero-point; check of cutting and machine operation in simulated form on the VIRTUAL MACHINING display	SET UP RECORD display for the setup data as a whole; WORK OFFSET display for the `G54` to `G59` zero-point offsets used by EIA/ISO programs; VIRTUAL MACHINING for the simulation

The tool-data half of that list is where most failed starts originate, and the control has a specific alarm for each way of getting it wrong. A milling tool named in the program but not registered in the tool file gives NO ASSIGNED TOOL IN TOOL FILE (434 when checking, 628 at run time). Tool length or diameter left blank on the TOOL DATA display gives TOOL DATA INPUT PROCESS ERROR (627, and 953 for the EIA/ISO and MDI case) or INCOMPLETE TOOL DATA (1107). Whether missing data stops you at all depends on parameter F84 bit 7 — set to 0, missing data is ignored and the program runs. That is worth knowing before you conclude the data must be fine because nothing complained.

The zero-point half splits by program type, which is the single most Mazak-specific thing about setup. A MAZATROL program carries its coordinate system in the program itself, in the basic coordinate system unit — leave it incomplete and you get DATA MISSING IN WPC UNIT (613). An EIA/ISO program uses the WORK OFFSET display, six coordinate systems G54 through G59, each holding the distance from machine zero to workpiece zero on every axis. Same machine, same job, two different places to look. The mechanics of both are covered in Probing on Mazak and Coordinate Systems & Offsets.

Starting, and What Refuses to Start

Between selecting the program and pressing start, Mazak inserts a step that has no equivalent on most controls: selecting the automatic operation execution conditions. These are menu items on the execution-conditions menu, available from the POSITION, TRACE, EIA MONITOR and PALLET MANAGEMENT displays, and they can be selected or cancelled during a run as well as before it. Some of them are hidden until you tap [TEST] — which is why an operator who has never seen the menu may swear their machine does not have dry run.

Then the cutting conditions: rapid traverse override (0 to 100 percent of the maximum set by parameter M1), cutting feed override (0 to 200 percent), spindle speed override (0 to 150 percent, in 10 percent steps). Then start.

When it refuses, the message is usually ILLEGAL CYCLE START (144), and the alarm itself is nearly useless on its own — the reason is carried in a sub-code displayed alongside it. The list is worth knowing because most of these are things you can see on the machine once you know to look:

Sub-code	Cause per the alarm list
`0x102`	NC ready signal is not ON
`0x103`	Reset state not yet cleared
`0x104`	Feed hold is in operation
`0x105` / `0x106`	Hardware overtravel / software overtravel not yet cleared
`0x107` / `0x108` / `0x109`	No operation mode selected; two or more operation modes selected; during change in operation modes
`0x110` / `0x114`	During editing on the EIA MONITOR display; program being edited on the EIA MONITOR display
`0x111`	During search on the tape data
`0x115`	A door opened
`0x118`	An alarm related to safety barrier not yet cleared
`0x120`	After establishing absolute positions through zero return operation, the power has not been turned off and back on
`0x124`	The cycle start button was pressed while the work number was being changed

Note 0x110 and 0x114 especially. Editing on the EIA MONITOR display while the machine is stopped is a normal and supported thing to do — but you must finish it by tapping [PROGRAM COMPLETE] before pressing start, or the control treats you as still editing. Mazak’s own warning on that workflow is blunt: operation will progress according to the edited program, so extra care is required.

Restarting in the Middle: Three Functions, Two of Them Safe

Start with the behavior that surprises people: reset does not preserve your place. After a reset, pressing cycle start runs the program from the beginning, not from where it stopped. If you want to resume, you have to say so with one of the restart functions.

There are three, and the difference between them is exactly the difference between walking the program forward and teleporting into it.

Function	How you specify the position	What happens to the modal state
Restart operation — `[RESTART]`	MAZATROL: pick the machining process in the SELECT PROCESS window, plus NUMBER (which repetition or workpiece) and REPEAT TIMES. EIA/ISO: enter work No., sequence No., block No., and how many occurrences of that sequence number to count past, then tap `[RESTART SEARCH]`.	Rebuilt. The program from its head to the designated block is internally processed to check for errors and set the modal information, then the machine positions to the end point of the preceding block and executes from there.
Smooth restart — the search button	The control finds the position itself, from information it stored about the interruption (a reset, an alarm, or a power failure). For EIA/ISO you choose between HOLD POSITION and the last TOOL CHANGE block.	Rebuilt, from stored interruption data. The setting window shows you the modal S, F, M, B and G conditions and the M-codes executed up to that block before you commit. May not be fitted on every machine.
Restart 2 non-modal — `[RESTART2 NONMODAL]`	Put the cursor on a block on the EIA MONITOR display and tap the menu item. That is the whole procedure.	Not rebuilt. Mazak’s wording: “with the preceding program section being ignored, restart operation will be begun with the execution of the designated block, on the basis of the modal information currently valid.”

⚠ The non-modal trap. [RESTART2 NONMODAL] is the fast one, and it is fast precisely because it does not read the program above the cursor. The tool call, the work offset, the spindle start, the coolant, the compensation, the feed — none of it happens. Mazak’s instruction is to set the modal state yourself first, in MDI mode, before selecting the block. Use it when you know exactly what state the machine is in and have put it there deliberately. Use [RESTART] or Smooth restart when you do not.

Both of the rebuilding functions let you enter up to six M-codes to be executed preparatory to the restart — the manual’s worked example is M19, spindle orient. This is the mechanism for putting the machine into the physical state the restart block assumes, and it is the piece most people never discover. Beyond M-codes, Mazak lists what must already agree with the restart position before you press start: for EIA/ISO programs the pallet number and the M-, S-, T- and B-codes; for MAZATROL programs the pallet number, the index angle, and the position of the 4th axis.

Three limits that are easy to hit. You cannot restart from the middle of a MAZATROL subprogram at all. You cannot restart into an EIA/ISO subprogram called from a MAZATROL main program, or vice versa. And a sequence number inside a high-speed machining section (G05 P2) can never be found, because the control skips those N numbers as meaningless — the search will always fail. When a search fails you get an alarm rather than a silent no-op: RESTART SEARCH UNFINISHED (448) if you press start without searching, RESTART TIMES EXCEEDED (446) if the block exists but the occurrence count you gave is too high, and PROGRAM ERROR (447) if the search hit an error in the program on the way through.

One more that catches everyone once: on EIA/ISO restart, the initial move to the restart position is made using dry run when parameter K104 bit 7 is 0. If the manual feedrate happens to be set to zero, the restart raises FEEDRATE ZERO (132) the moment you press start.

What Throws Away the Restart Information

Smooth restart depends on stored information about the interruption, and a list of ordinary-looking actions deletes it. Mazak notes that this happens even if the program you touched is not the foreground program. While an interrupted run is waiting to be resumed, avoid:

• Pressing the power-off button
• Replacing the foreground program with another one on the POSITION display
• Renumbering or renaming a program on the PROGRAM FILE display
• Deleting a program, moving one to another storage area, or using [PROGRAM COPY]
• Converting a MAZATROL program into an EIA/ISO program
• Loading a program on the DATA I/O display
• For EIA/ISO specifically: editing any program

For MAZATROL programs there is a softer version of the same problem. If the program layout has changed in the meantime — a priority number edited, a unit copied, inserted or erased, [PROGRAM WRITE] executed on the PROGRAM LAYOUT display — the SELECT PROCESS window can only open in its initial state, with the cursor on the first process. The search still runs; it just no longer knows where you were.

Two behaviors round this out. A restart search, once finished, stays finished: the completion status is released only by pressing reset, and until you do, the control will refuse a second search or a work number change with RESTART SEARCH FINISHED (449). And if you restarted with [RESTART2 NONMODAL] rather than [RESTART], Smooth restart cannot be used afterwards — the non-modal path does not leave behind the information Smooth restart needs.

Proving Out

The execution-conditions menu is where prove-out lives. Everything here can be toggled during a run as well as before it.

Function	What it does	Watch for
Single Block	Executes one block per press of cycle start. Selecting it mid-run stops the machine at the end of the current block.	The one to run part one in. Costs minutes once.
Optional Stop	Stops at the end of any block containing `M01`. In a MAZATROL program the code goes in an M-code unit (items M1 to M12) or a machining unit’s sequence M item; in EIA/ISO, any block.	Restart resumes from the next block.
Dry Run	Runs at a manually adjusted feedrate instead of the programmed one. Selecting it drops the machine into feed hold and swaps the override display to the manual-operation reading, showing `DRYRUN WORKS CHECK OVERRIDE`.	Motion happens at the last manual feedrate, not a percentage of program feed. Check that number before you start.
Machine Lock	Runs the program with no axis movement; the position counters advance as if the moves happened.	Do not cancel it during automatic operation. The stored machine position no longer matches the real one, and axis motion after cancelling happens in a disturbed coordinate system. Press reset after disabling it to restore a correct position display.
MST Lock	Skips M-, S-, T- and B-codes entirely. `M3` is not output and the spindle does not turn.	Select it together with Dry Run. Without dry run, a feed-per-revolution command raises `STOP SPINDLE` (`133`).
Z-axis Cancel	Runs with no movement of the Z axis.	Same family of hazard as machine lock.
Block Skip	Skips blocks starting with `/`, or `/1` through `/9` selected individually from a submenu.	EIA/ISO only. Also: Smooth restart cannot account for it at all, so a run made with block skip active may compute a restart position that is not where you actually stopped.
Comparison Stop	Forces a single-block stop at a position you name by work No., sequence No. and block No.	EIA/ISO only. The tidy way to stop just before the move you are worried about.
ATC Stop	Stops the machine when machining with the current tool finishes.	Useful for inspecting one operation without babysitting the whole program.
Trial Mode	Purpose-built for the first workpiece of a MAZATROL program. Automatically stops the program and the coolant at the approach and escape positions, can cap rapid traverse to a set rate and override, and can stop short of the cutting start point by a remaining distance you specify. Displays `TRIAL MODE STOP` when it halts.	MAZATROL programs only. Its settings survive a power cycle but the mode itself is cancelled at power-on, and the settings cannot be changed while it is active or during automatic operation.

Off the machine there is also Virtual Machining — work simulation of the cutting process against material and fixture, and machine simulation of the components moving — which is the step Mazak puts in its own preparation checklist. Note the interaction: Virtual Machining can run in parallel with automatic operation only if the SAFETY SHIELD function for automatic operation is invalid. And the TPS function is the complement for when a run is already in trouble: it stores up to five tool-tip positions during a manual interruption so that after you have moved the tool away to clear a chip or swap a broken insert, cycle start returns the tool to the stored position and resumes without disturbing the programmed path.

Alarms While Trying to Start a Program

The curated set — the ones that stop you before the first chip, rather than the full list. Alarm numbers and texts below are identical between the SmoothAi and SmoothG alarm lists.

Message	Number	What it means and what to do
Cannot start at all
ILLEGAL CYCLE START	`144`	Automatic operation was attempted under a condition that forbids it. The sub-code is the whole message — read it and check the table above. Also `1124` for starting hard disk, Ethernet, IC card or tape operation while the automatic-operation INTELLIGENT SAFETY SHIELD is valid.
NOT AUTO MODE	`146`	Automatic operation was started in a mode other than an automatic mode. Change the mode. Number `1473` is the same text for a different cause: attempting the restart 2 non-modal setting outside memory or hard disk operation mode.
NO OPERATION MODE	`130`	Incorrect mode selection or a malfunctioning automatic operation key. If reselecting the mode does not clear it, this one is a service call.
MACHINE DOOR INTERLOCK	`232`	The machine was operated with the door open. Close it. This is also `144` sub-code `0x115` if you catch it at the moment of starting.
AXIS NOT ZERO RETURNED	`880`	A move other than a reference-point return was commanded on an axis that has not been returned to its reference point. Return it manually.
Wrong program, or none
PROGRAM No. NOT FOUND	`405`, `844`	`405`: you selected a work number that is not registered. `844`: a subprogram call at run time refers to a program that is not registered.
DATA MISSING IN WPC UNIT	`613`	The MAZATROL basic coordinate system unit is incomplete. The program has no zero point to work from.
MEMORY PROTECT (AUTO OPERATION)	`428`	You tried to enter data the control will not accept during automatic operation — on the TOOL DATA display, for example. Reset or change mode first.
Tool data not ready
NO ASSIGNED TOOL IN TOOL FILE	`434`, `628`	A milling tool named in the program is not registered on the TOOL FILE display. Register it.
TOOL DATA INPUT PROCESS ERROR	`627`, `953`	Tool length or diameter is blank on the TOOL DATA display. `953` is the EIA/ISO and MDI case, and only fires when MAZATROL tool length/diameter are valid and `F84` bit 7 is 1.
INCOMPLETE TOOL DATA	`1107`	Manual tool measurement cannot compute because data items are blank, or an MDI program ran with tool length or nominal diameter unset.
Restart went wrong
RESTART SEARCH UNFINISHED	`448`	You pressed start without running the EIA/ISO restart search. Designate the position and search first.
RESTART SEARCH FINISHED	`449`	A second search, or a work number change, after the search already completed. Press reset, then start over.
RESTART TIMES EXCEEDED	`446`	The block exists but the occurrence count you entered is larger than the number of times it appears.
PROGRAM ERROR	`447`	The restart search hit a program error on its way through. Run a tool path check on the program.
Zero where a number should be
FEEDRATE ZERO	`132`	Cutting feed or dry run attempted with the manual feedrate at 0 — classically, right after a restart search. Also `621` for an unset feedrate in MAZATROL tool sequence data and `816` for a missing F in EIA/ISO.
CUTTING FEED OVERRIDE SET AT 0	`131`	The cutting feed override switch is at zero. Turn it up.
STOP SPINDLE	`133`	Spindle rotation did not start when commanded. Check the program and tool data — and check whether MST Lock is on without Dry Run.

Alarms appear in the alarm display area of the screen and some cannot be cleared with the alarm clear button. For the number classes, the type/stop/clear coding, and a wider table, see Mazak Alarms & Parameters.

SmoothAi and SmoothG: Where They Differ

Less than you would expect for running programs, and the manual set says so structurally. Mazak publishes one AUTOMATIC OPERATION book covering MAZATROL SmoothAi and MAZATROL SmoothG together — the restart functions, the execution-conditions menu, the override ranges and the stopping methods are the same text for both. The alarm numbers and messages in the two Parameter/Alarm/M-Code lists match as well.

The NC-unit operating manuals are published separately (H747S31000E for SmoothAi, H749S31001E for SmoothG) and are near-identical in structure — same POSITION, TOOL DATA, WORK OFFSET, PROGRAM FILE, TRIAL MODE and VIRTUAL MACHINING displays, same preparation chapter word for word. The SmoothAi book adds a small number of sections its SmoothG counterpart does not have, among them setting the STATUS LIGHT and correcting the sensitivity of the touch panel. If you move between a SmoothG machine and a SmoothAi machine, the running-a-program workflow transfers intact. What differs between the two generations beyond that is outside the scope of these operating manuals — see Mazak Control & Family Guide for the wider comparison.

Habits That Prevent Most of This

Decide up front whether you are resuming or restarting. Reset means “from the top.” If you want to resume, do not press reset, do not swap the foreground program, and do not edit anything — then use [RESTART] or Smooth restart deliberately. Most lost-restart frustration is drift between the two intentions.

Use the M CODE field. Six M-codes before the restart block is the tool Mazak built for putting the machine into the state the block assumes. Spindle orient, coolant, whatever the section needs. Restarting without it and hoping is the common failure.

Treat non-modal restart as a sharp instrument. [RESTART2 NONMODAL] ignores everything above the cursor by design. If you have not set the modal state yourself in MDI first, you are guessing at what the machine will do.

Run part one in Single Block with the overrides down. One press per block turns a crash into a pause, and rapid override is a switch, not a setting you have to program. On a MAZATROL program, Trial Mode automates the same caution at every approach and escape.

Check the tool data before the program, not after the alarm. Registered in the tool file, length and diameter set, layout confirmed. And remember that F84 bit 7 can be set so the control says nothing about missing data at all.

References

Mazak, Operating Manual — MAZATROL SmoothAi (for Machining Centers): Operating NC Unit and Preparation for Automatic Operation, H747S31000E, 02/2020 — Chapter 1 (preparation steps), 5-3 (EIA MONITOR, RESTART 2 NONMODAL), 5-9 (TRIAL MODE), 6-1/6-2 (SET UP RECORD, WORK OFFSET), 7-2/7-4 (TOOL PATH CHECK, PROGRAM FILE and work numbers), 8-1 to 8-3 (TOOL DATA, TOOL FILE, TOOL OFFSET), 12-4 (VIRTUAL MACHINING). Supplied with the VARIAXIS C-600.
Mazak, Operating Manual — MAZATROL SmoothG (for Machining Centers): Operating NC Unit and Preparation for Automatic Operation, H749S31001E, 04/2022 — used for the SmoothAi/SmoothG comparison. Supplied with the HCN-5000.
Mazak, Operating Manual — MAZATROL SmoothAi (Machining Center / INTEGREX i / VORTEX i): Automatic Operation, H747S41001E, 04/2020 — Chapter 1 (execution procedure, operation modes, restart and Smooth restart, single-process, MDI), Chapter 2 (execution conditions), Chapter 3 (overrides), Chapter 4 (stopping), Chapter 5 (manual interruption, TPS).
Mazak, Operating Manual — MAZATROL SmoothAi and MAZATROL SmoothG: Automatic Operation, H747S41006E, 08/2022 — the shared edition covering both control generations. Supplied with the HCN-5000.
Mazak, Parameter List / Alarm List / M-Code List — VARIAXIS C-600, NC: MAZATROL SmoothAi, HD28HA0010E — alarms 130, 131, 132, 133, 144, 146, 232, 405, 428, 434, 446, 447, 448, 449, 613, 627, 628, 844, 880, 953, 1107, 1124, 1473.
Mazak, Parameter List / Alarm List / M-Code List — HCN-4000/HCN-5000 series, NC: MAZATROL SmoothG, HE00HA0066E — cross-checked for identical alarm numbering and message text.