2.2 Installation and spacing
All PNOZmulti devices must be installed vertically on a horizontal DIN rail with ventilation slots facing up/down. Other installation directions may cause overheating damage.
The protection level of the control cabinet should be at least IP54.
Maintain a minimum distance of 40mm and 20mm from other devices above and below. If the installation space is too compact, the chip card may be difficult to insert and remove. In this case, the base should be removed before replacing the chip card.
To meet EMC requirements, DIN rails must be connected to the control cabinet ground with low impedance.
2.3 Wiring taboos
Test pulse outputs: can only be used to detect input circuits (such as short circuits across emergency stop contacts), and it is strictly prohibited to drive any loads (relays, indicator lights, etc.). If the test pulse is mistakenly connected to the coil, it will immediately trigger the "FAULTRAY TEST PULSE" error and cause the safety output to shut down.
Feedback loop: When using redundant contactors, the auxiliary contacts of the contactors must be connected to the feedback input terminal (such as I14 or IM16). One of the most common reasons why the safety output cannot be restarted is due to wiring errors in the feedback loop.
Power isolation: The system power supply (A1/A2) and semiconductor output power supply (24V/0V) of the basic unit can share a 24V power supply, but if they are supplied separately, both must always be maintained. Even without using semiconductor output, the output power terminal must still be powered on.

Project loading and chip card: common fault points
The projects of PNOZmulti system are stored in chip cards. The basic unit itself does not retain the project, and will reload from the chip card every time it is powered on or reset. Therefore, chip card related malfunctions are the most common cause of downtime.
3.1 Chip card type
8 kByte (Order Number 779201/779200)
32 kByte (Order Number 779211/779212)
Large projects (exceeding 8 kByte) must use a 32 kByte card. If a low capacity card is used to store large projects, it will report "FAULTRAY PROJECT" when loading.
3.2 Project loading steps (Mini model with display screen)
Insert the chip card (pay attention to direction, do not bend).
Connect the power supply. The display screen will show the project name, CRC checksum, and creation date.
Press and hold the knob for 3-8 seconds until the loading progress is displayed. If the holding time is too short or too long, the project will not download.
After success, the RUN LED stays on and the display switches to the I/O status view.
3.3 Common Chip Card Malfunctions and Solutions
Error display meaning solution
CHIP CARD ? Clean the chip contacts without inserting a card, with a blank card or poor contact; Reinsert; Replace chip card
FAULTRA PROJECT: If the project in the card is damaged or incompatible with the firmware version, use PNOZmulti Configurator (same or higher version) to regenerate the project and download it to the card
After loading, there is no response. The RUN LED is off and the knob is not pressed correctly. After turning off the power, press and hold the knob for about 5 seconds until "Loading" is displayed
Display 'CRC: 0x0000' item as empty or no valid configuration in the card. Download the item again to the chip card via USB
3.4 Download via USB (without knob)
For Classic base units without display screens, or Mini models without knobs:
Connect the Mini USB cable (3m/5m order number 312992/312993) to the computer.
Execute 'Transfer to Device' in PNOZmulti Configurator. Note: The chip card must still be inserted as the final storage medium.
LED indicator light diagnosis: one minute quick positioning
The LEDs on the PNOZmulti base unit and expansion module are the fastest diagnostic entry point on site. Taking the six LEDs (PWR, RUN, DIAG, FAULT, I FAULT, O FAULT) shared by Classic and Mini as an example.
LED combination meaning action
Measure A1/A2 voltage (24V DC ± 20%) when the PWR power is turned off or the internal fuse is damaged; Check the external switch
RUN is turned off, FAULT flashing item is deleted or chip card is invalid, reload item
FAULT stays on, DIAG flashes, external error causes safety status: chip card not inserted, feedback loop fault, test pulse short circuit. Check chip card; Check the wiring of the feedback loop; Disconnect the load on the test pulse output
I FAULT is constantly on due to external input errors (but may not necessarily cause the safety output to be turned off), such as emergency stop with only one channel closed. Check the input signal and wiring
Output external error (safety output overload, short circuit, or feedback loop abnormality) when the O FAULT is constantly on. Measure the resistance of the output terminal to ground; Check if the load current exceeds 2A/point
RUN is constantly on, but all safety outputs are non-conductive. Internal logic conditions are not met, or the startup circuit is not reset. Check the startup button wiring and configuration of the startup type (automatic/manual)
I FAULT and O FAULT flash simultaneously. Internal hardware error. Replace the base unit