How Do You Restart a Hit8S SINUMERIK 840C After Data Loss?

After the correct machine data, PLC application, panel input states, and drive-power interlocks are restored, the Hit8S starts normally: the machine-control panel becomes active, POWER ON starts the hydraulics, the axes reference in JOG REFPOINT, and the spindle accepts an MDI command. Treat data recovery, panel recognition, drive readiness, and spindle feedback as separate commissioning gates.

Recovery Boundary and Data Preservation

A SINUMERIK 840C general reset can clear NCK, PLC, correction, R-parameter, and drive-related memory. Removing the battery is not the normal method for clearing these areas. Use the selections in GENERAL RESET, because they define which memory regions are erased.

If the control still boots, record the tool tables, user parameters, axis limits, option settings, and active machine configuration before clearing memory. The Hit8S disk can contain multiple data sets, including versions for a bar feeder. A machine formerly equipped with a bar feeder may still require its original machine data with the feeder disabled by the intended PLC logic; loading a superficially similar no-feeder set can change unrelated functions.

File dates alone do not prove that a backup matches the machine. Compare the available sets, especially option differences such as the bar-feeder selection and machine parameter 8000.0, identified here as the eight-position turret setting.

1. Inventory the machine-specific files, standard files, ANW_PROG copies, and user tables.
2. Record which data set was active before the reset, if that information remains available.
3. Do not perform another drive reset until the installed drive type has been identified.

Check 1: Expect a recoverable copy of the NCK, PLC, cycles, and user data, plus a documented choice between the bar-feeder and no-feeder configurations.

CSB Forced-Boot State and Standard Data

The CSB rotary switch establishes the commissioning startup condition. Use position 4 while loading the base files, then return it to 0 before closing the general reset. Leaving the switch in the commissioning position prevents a normal production startup.

1. Set the CSB switch in the cabinet to position 4.
2. Power the control and wait for the Siemens screen.
3. Open DIAGNOSIS / START-UP / GENERAL RESET. Enter password 1111 if requested.
4. Select FORCED BOOTING NCK.
5. Press RECALL once and select NCK POWER ON.
6. Open MACHINE DATA / FILE FUNCTION.
7. Use the diagonal-arrow key to select the upper file window. Load the standard TEA1 file with Load from disk / Load start.
8. Load the standard TEA2 and TEA4 data in the same way.

The upper and lower windows have different roles during this process. Selecting the wrong window can expose a plausible filename from the wrong directory, so confirm the active pane before every transfer.

Check 2: Expect each standard-file transfer to complete without a message that the selected file lacks the requested machine-data area.

Machine-Specific NCK, PLC, and Cycle Data

The standard files create a base configuration; they do not contain the Hit8S application. Load the machine-specific areas separately so the NCK, PLC, and cycles receive data intended for their respective memory regions.

1. Return once with RECALL and enter NC MD / File function.
2. Select the lower window and load the applicable HIT8S machine file.
3. Return once, enter PLC MD / File function, and load the machine-specific PLC data.
4. Return once, enter CYCLES MD, and load the machine-specific cycle data.
5. Review the selected Hit8S set for the bar-feeder option and turret configuration before committing it as the working set.

A coolant output clicking does not prove that the full PLC application is correct. Default logic, partial data, or a surviving output path can operate one relay while the machine-panel and hydraulic-start sequences remain unavailable.

Check 3: Expect completed transfers in all three destinations and confirm that the loaded set matches the machine options rather than merely sharing the Hit8S name.

General-Reset Closure

Close the commissioning session only after all required data areas have been loaded. The reset selections erase and rebuild different subsystems; selecting every option without identifying the installed hardware can create another recovery task.

1. Set the CSB switch back to 0.
2. Return to the main level by pressing RECALL exactly three times.
3. Enter GENERAL RESET.
4. Select FORMAT NCK AWS.
5. Select PLC general reset.
6. Do not select DRIVE General reset for the analog drive arrangement described here.
7. Select END GENERAL RESET and wait for the control to leave reset mode.
8. Power the system off when the reset sequence has completed, then restart it normally.

A full memory clear may also remove correction data and R parameters. Use it when stale data prevents a clean reload, but restore the recorded user values afterward.

Check 4: Expect the control to exit general-reset mode without remaining at the reset screen. Failure to exit directs the next check to the PLC application file.

PLC Application File Recovery

ANW_PROG is the PLC application file required for the machine-specific sequence. A missing or corrupt copy leaves the PLC CPU unready, disables DMP outputs, and prevents normal panel and hydraulic operation. Alarm 43 ORD1 PLC-CPU not ready for operation, a red PLC indication, red DMP station indication, and inactive output LEDs form a useful diagnostic group.

1. Open the PLC directory and inspect ANW_PROG.
2. If it is missing or unusable, rename the existing file to preserve it.
3. Perform a PLC general reset to clear the PLC memory.
4. Locate the available backup copies and choose the newest applicable machine copy. File content matters more than the timestamp; compare copies when possible.
5. Copy the selected file into the PLC directory and name it ANW_PROG.
6. Perform the PLC general reset again.

Removing ANW_PROG should make the machine noticeably worse if the previous file was executing: the PLC-ready indication drops, DMP outputs turn off, and alarm 43 appears. Restoring a valid copy should reverse those symptoms.

Check 5: Expect the PLC CPU to reach its ready state, the DMP error indication to clear, and commanded outputs such as coolant control to appear at the relevant output LEDs.

DMP Machine-Control-Panel Recognition

The machine-control panel can operate as a DMP module even when 1st machine control panel available is shown as no. For the documented DMP case, PLC MD 6066/67 bit 0=0. Changing that setting to yes can select a different panel architecture and produce alarm 2000 ORD1 emergency stop.

The keyboard module is 6FC5103-0AC02-0AA1. Its DMP address was set by rotary switch position E, corresponding to address 64. Changing the address caused relays to drop, the keyboard-module red H2 LED and DMP connector error LED to illuminate, and alarm 43 to appear. That reaction proves that address agreement affects PLC readiness.

At connector X221, each input has a 1 k pull-up resistor. Pins 36, 40, and 44 are high-active; the remaining inputs are low-active. The three high-active keys must present the required low startup level when the control is switched on. The documented contacts are normally closed. The recovered installation associated this recognition problem with the POWER ON, FEED HOLD, and SPINDLE STOP circuits, while another description names an NC-hold function. Resolve the label ambiguity by matching connector pins, the wiring diagram, and live input bits.

Check 6: Expect keyboard LEDs H1-H3 to run their startup sequence and the red indication to extinguish without a DMP communication alarm.

Live MCP Input-State Verification

Use the PLC status display instead of judging the panel solely by lamps. Open Diagnosis / Service display / PLC service / PLC status. The term IB means input byte; IW means input word containing two adjacent bytes. DMP address 64 appears as input word IW 64, followed by subsequent words for the remaining panel data.

1. Display IW 64 and the following input words.
2. Record every bit with all controls released.
3. Operate one pushbutton or selector at a time and record the changed bit.
4. Compare the inactive level with the contact type and active polarity, especially for the three startup-sensitive inputs.
5. Check CYCLE START separately. A permanently active start input caused abnormal operation because its default PLC state remained 1.
6. Power-cycle the control with all startup-sensitive inputs in their required recognition state.

The installation notes contain a contradictory NO/NC wording for the final contact changes. The deciding measurement is the live inactive bit: the contact must create the startup level required at the corresponding DMP input, then change state once when actuated. Reassigning contacts by label alone is wrong practice.

Check 7: Expect every key and selector to change exactly one mapped PLC input as intended, panel lamps to become available after startup, and POWER ON to illuminate and start the hydraulic pump when pressed.

SIMODRIVE 611 Power-Supply Readiness

The installed SIMODRIVE 611 arrangement uses analog drives. Its drive-configuration screen can therefore remain empty, and digital-drive data loading does not apply. Alarm 165002 No data has been transmitted means the selected file does not contain the required machine data; the prescribed action is to select another file. The candidate HIT-8S.108 contained only zero-valued drive parameters, so it did not supply a usable digital-drive configuration.

Observation	Meaning or next test
No LED on 6SN1145-1BA01-0BA0 with 3x400 V present	Diagnose the power supply and its protection circuits; this installation had an internal auxiliary-supply fault.
Green LED immediately after mains application	Expected initial supply indication.
Green extinguishes and orange/yellow DC-link indication appears after control enable	Expected enabled transition when the interlocks and power stage are healthy.
ARDY at terminal 72	Drive-ready output, not an enable input.
Terminals 63 and 64 at 24 V	Pulse-enable and drive-enable requests are present.
Terminal 9 at 24 V	Control supply state present in this installation.
Terminal 19	Was not connected; check the applicable circuit before assigning a function.
NS1-NS2 open	Missing jumper blocks the supply. The jumper was accidentally moved when two similar two-pin plugs were exchanged.

Terminal 63 belongs to the power-supply enable check discussed here; 663 is associated with the feed modules. Do not interchange these identifiers. A DC-bus short can also prevent the DC-link indication, so isolate the bus only under the drive service procedure and test the power section before reconnecting it.

Check 8: Expect the correct initial green indication, the enabled DC-link indication, and a valid ARDY output after confirming NS1-NS2, terminals 63, 64, and 9.

Spindle Feedback and Power-Stage Diagnosis

Alarm 20140 ORD2 speed setpt value alarm limit responded, rapid spindle jerks, an unstable actual-speed display, zero position, and a full-scale load indication point to a failed speed-control loop or power stage. Do not raise a tolerance to hide this symptom. The diagnostic list for the alarm includes the drive, position-control direction, spindle multiplication gain MD 468*, speed-setpoint cable, actual-value or pulse-encoder feedback, spindle-speed tolerance MD 445*, and acceleration time constants MD 419*–426*.

1. Stop repeated spindle-start attempts when the load meter reaches maximum.
2. Inspect the mechanical connection between the spindle and encoder. The encoder belt in this machine had worn teeth.
3. Check encoder motion and the actual-value signal through the complete cable path. Physical encoder rotation alone does not prove valid feedback.
4. Verify motor connections and phase order if the motor or drive wiring was disturbed.
5. Test the spindle inverter power stage. One IGBT module was shorted in this installation; replacing only the encoder belt did not remove the jerking.
6. After hardware repair, compare commanded and displayed speed. A displayed speed exactly one-half of the setpoint directs attention to feedback scaling, encoder ratio, and the applicable spindle multiplication data.
7. With the belt removed, compare motor and spindle noise. Normal motor operation with a very noisy coupled spindle isolates the remaining mechanical problem toward the spindle bearings.

Message 9203 Spindle hold from operator panel is a status warning that spindle permission is off at the panel, not the cause of a shorted IGBT. Operate the green spindle-symbol key and confirm its PLC input before diagnosing the drive.

Check 9: Expect a stable actual-speed value, a load indication below its limit, correct command-to-feedback scaling, and smooth rotation without alarm 20140.

End-to-End Commissioning Sequence

1. Power on and verify that the PLC, DMP panel, and SIMODRIVE supply all reach their ready states.
2. Press POWER ON. Expect its lamp and the hydraulic pump to turn on.
3. Select JOG REFPOINT and reference the axes.
4. Select AUTOMATIC, open program selection, select L965, and press CYCLE START. L965 establishes the measuring plane and must run at least once after startup and whenever that plane changes.
5. Index the turret and verify two tool positions against their physical stations.
6. Open Menu select / Setting data / Axis limitation. The recovered startup procedure specifies G26=4000 and G92=4000; compare these values with the machine specification or the approved job limit before entering them.
7. For a controlled spindle test, select MDI and command M3 S500.
8. Confirm spindle permission at the panel, smooth acceleration, matching commanded and actual speed, normal load, and no alarm 20140.

Check 10: Expect the panel to respond from a released-key startup state, hydraulics to start only through the intended POWER ON sequence, axes to reference, the turret to index correctly, and M3 S500 to produce stable spindle operation.

FAQ