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Working documentation

This page is generated from the project's working notes. It records a real retrofit in progress, corrections included. Anything marked 🔴 or ⚠️ is unresolved or carries a caveat - read those before acting.

The safety and enable chain

2 September 2026. From wiring diagram sheets 11 (AUX INSERITI), 12 (CIRCUITO AUX), 13 (CIRCUITO AUX - MOTORI FERMI and INTERVENTO TERMICI), 14 (ALIM. AZIONAMENTI command) and 15 (CIRCUITO AUX - drive relays).

This is the most retrofit-critical structure in the machine. It is entirely in hardware and almost none of it appears in MW310.PLC.

The enable chain

OF.1  "CNC OK"  (wire 17, sheet 11)
  |
  +--> -SA1 key selector --> -KA coil
         |
         +--> KA and KA2 contacts gate rail 8 into rail 8A  (sheet 11)
                |
                +--> -KAX coil, returned via the X drive's ALM contact (wire 72)   [sheet 15]
                +--> -KAY coil, returned via the Y drive's ALM contact (wire 86)
                +--> -KAZ coil, returned via the Z drive's ALM contact (wire 100)
                +--> -KAF coil, returned via the Z drive's CN1 pin 27 (wire 35)
                       |
                       +--> KAF contacts --> Z brake -FR.Z  (sheet 9)
                |
                +--> KAX contact 10-6 --> wire 195 --> -KMX coil --> X axis mains contactor  [sheet 14]
                +--> KAY contact 10-6 --> wire 197 --> -KMY coil --> Y axis
                +--> KAZ contact 10-6 --> wire 199 --> -KMZ coil --> Z axis
                       (the other side of each changeover lights -HLX / -HLY / -HLZ,
                        wires 194 / 196 / 198, so the red lamp means that axis is NOT healthy)
                |
                +--> -KM560 coil --> carousel contactor
                |
                +--> -KTI timer + KMX aux 13-14 --> -KMI coil --> inverter contactor

What this means for the retrofit

🔴 OF.1 is the master enable, not a status light. Dropping it opens every axis contactor and applies the Z brake. Mesa's OF.1 must therefore be a genuine hardware watchdog output, not a software-set output, or a hung PC leaves the machine powered.

✅ The whole chain can be inherited untouched. Mesa drives OF.1, everything downstream keeps working exactly as built: per-axis alarm gating, per-axis contactors, per-axis fault lamps, the Z brake.

✅ Per-axis fault indication comes free. HLX/HLY/HLZ already light when their axis drive is not healthy.

The fault chain - what IF.8 actually is

Sheet 13, INTERVENTO TERMICI:

rail 8
  --> -QF101 /2.4   (drills motor breaker)      --> 125
  --> -QF601 /2.6   (vacuum pump breaker)       --> 126
  --> -QFINV /5.6   (inverter breaker)          --> 127
  --> -QFX /4.1     (X drive breaker)           --> 128
  --> -QFY /4.3     (Y drive breaker)           --> 129
  --> -QFZ /4.6     (Z drive breaker)           --> 130
  --> -QF560 /4.8   (carousel breaker)          --> 131
  --> -KA562 /10.6  (carousel relay)            --> 133
  --> -KAX /15.2    (X drive OK)                --> 134
  --> -KAY /15.4    (Y drive OK)                --> 135
  --> -KAZ /15.6    (Z drive OK)                --> 19
  --> FAULT INVERTER  (wires 19 / 20, from sheet 5.5)
  --> -KA4 coil (with flyback diode) --> wire 7

KA4 contacts: 9-5 to 11.8, and 12-8 to 16.8.

Sheet 16 column 8 is EIN8, which is IF.8 IF_EMERG_TERM.

🔴 So IF.8 is a summary fault input, not a mushroom-button E-stop. It opens if:

  • any of the seven motor-protection breakers trips, or
  • any of the three servo drives raises its alarm, or
  • the carousel relay KA562 drops, or
  • the inverter faults, or
  • the emergency chain on sheet 11 opens (which kills rail 8 upstream)

⚠️ Correction to earlier notes. mw310-recon.md and HANDOVER.md describe IF.8 as "the E-stop chain". That is too narrow. The Italian on sheet 16 says EMERGENZA TERMICI - thermal overload emergency - and the drawing bears it out. The rope switch cleared the 0.0.0090 fault because the emergency chain feeds this rail, not because IF.8 is the rope switch.

Revised checklist for the next 0.0.0090

The existing checklist in HANDOVER.md (rope switch, mushrooms, door interlock, then start) stays valid but is incomplete. Add, before suspecting wiring:

  1. The seven motor-protection breakers: QF101, QF601, QFINV, QFX, QFY, QFZ, QF560. Any one tripped drops IF.8.
  2. The three drive fault LEDs on the SGDH front panels, and the axis lamps HLX/HLY/HLZ - a lit lamp names the faulty axis directly.
  3. The inverter's fault state.
  4. IF.29 End-Cycle remains the other branch of the error code.

The emergency chain proper (sheet 11)

The AUSILIARI INSERITI circuit runs from rail 2 through, in series: -SB1 start, -KM101 NC aux, -KMI NC aux, -SE1 (mushroom E-stop, ZB4-BS844), -KAA, -KA2, to wire 126.

A second branch inside =BM+X3 carries -SE2 (mushroom, ZB5-AS844) between -X3 29 and -X3 28, with a PONTE (link) drawn across -X3 29 to -X3 30, plus -SQF1 (bridged by wire 30) and -SP1 (pressure switch) to -X3 50 and -X3 A201.

⚠️ The rope switch is not named on this sheet. It is most likely SE2 or another device landing on that =BM+X3 terminal group. Worth identifying positively before the retrofit, since it is a guarding device that must survive. Note also the PONTE bridges: at least one position in this chain is linked out, presumably for an option this machine does not have.

KAMF - the guard interlock

Sheet 13, MOTORI FERMI: -KAMF's coil is fed from rail 2 through -KM200's NC auxiliary (21-22), so KAMF is energised when the spindle contactor is open.

Its contacts appear at 11.8, 12.1 and 17.8. On sheet 12 it is in series with the guard release solenoid -SQC. The guard cannot be released while the spindle contactor is closed. Another hardware interlock that must be preserved.

-KAA is energised from rail 2 in parallel; contacts to 11.1 and 25.5.

  • spindle-vfd.md - the inverter fault contact and the KM200 zero-speed gate
  • servo-drive-interface.md - the drive ALM outputs that feed KAX/KAY/KAZ
  • power-distribution.md - the breakers whose aux contacts form the fault chain