LTI Motion ServoOne PROFIBUS/PROFINET Troubleshooting and Replacement

LTI Motion ServoOne PROFIBUS/PROFINET Troubleshooting and Replacement

System Overview and Security Boundaries

The ServoOne series servo drives (including single axis systems, multi axis systems, and ServoOne junior) support both PROFIBUS and PROFINET fieldbus systems. PROFIBUS is based on RS-485 and adopts a master-slave polling mechanism, which is suitable for manufacturing and process automation; PROFINET is based on Ethernet TCP/IP and supports real-time (RT) and synchronous real-time (IRT), making it suitable for high dynamic motion control. Both follow the PROFIdrive device specifications to ensure consistent behavior of drivers from different manufacturers on the bus.

Safety always comes first. There is a dangerous voltage of 230V/460V inside the drive, which may still be charged within 10 minutes after power failure. Rotating components, automatically starting drivers, hot surfaces, and electrostatic discharge can all cause injury. Only personnel with electrical engineering qualifications and familiarity with accident prevention regulations such as BGV A3 can operate. Pacemakers, metal implants, and hearing aid wearers must stay away from the installation, maintenance, and operation areas of the drive system. Before debugging, it is necessary to read the relevant equipment manual, check the parameters, and prevent the driver from losing control due to changes in bus parameters.

PROFIBUS installation and address setting

The PROFIBUS interface is located on X14 of the ServoOne driver and is a 9-pin D-Sub socket that complies with the EIA-485 standard. Pin definition: 3 is B/B '(red, RxD/TxD-P）， 8 is A/A '(green, RxD/TxD-N）， 5 is DGND, 6 is VP (+5V terminal resistor power supply). Terminal resistors must be connected at both ends of the bus, with typical values: Ru=390 Ω connected to VP, Rd=390 Ω connected to DGND, Rt=220 Ω connected across pins 3 and 8. Use Siemens 6GK1500-0FC10 bus connector (with axial cable outlet) and 6XV1830-0EH10 standard cable. The maximum cable length depends on the baud rate: 9.6 to 187.5 kbit/s is 1000m, 500 kbit/s is 400m, 1.5 Mbit/s is 200m, and 3 to 12 Mbit/s is 100m. Up to 32 bus users can be extended into a tree structure through repeaters.

There are three ways to set the address: encoding switches S1 and S2, bus address parameter P-0918 in DriveManager 5, and integrated control unit. The encoding switch is used for single axis and multi axis systems, with a setting range of 0 to 125, where S1 is high and S2 is low, for example, address 12, S1=1，S2=2。 When using parameter P-0918, the encoding switch must be set to greater than 125 (such as 0xFF) to take effect. The integrated control unit selects "Fb" through buttons T1 and T2, sets the hexadecimal address, and saves by pressing T1 and T2 to "ok". After any address change, the device must be restarted. The address must be unique and cannot be duplicated.

PROFIBUS LED diagnosis: H1 yellow indicates cyclic data exchange, H2 red and H3 green indicate status. Power on self-test: If both H2 and H3 light up at the same time, it is reset. If H2 lights up and H3 lights up, it is ASIC RAM testing. If H2 lights up and H3 lights up, it is testing completion. Diagnostic status: H2 off and H3 flashing indicate "seeking baud rate", H2 off and H3 constantly on indicate waiting for parameter data, H2 off and H3 off indicate communication but no Class 2 connection. H2 flashes twice and stops once to indicate 'clear state', flashes twice to indicate parameter data error, and flashes three times to indicate configuration data error. H2 flashes 3 times and H3 goes out, indicating data exchange with Class 2 connection. H1 lights up during normal cyclic data exchange.

PROFINET Installation and Diagnosis

The PROFINET interface uses RJ45 sockets X47 and X48, which comply with the EIA/TIA-568B standard. Pin 1 is Tx Data+(white/orange), 2 is Tx Data - (orange/white or orange), 3 is Rx Data+(white/green), and 6 is Rx Data - (green/white or green). Support automatic negotiation, automatic crossover, and automatic polarity. PROFINET supports line, star, tree, and ring topologies, and integrated switches do not require additional network components. The cable uses standard Ethernet jumpers (such as S/FTP Cat. 5e) with a maximum length of 100m.

PROFINET LED diagnosis: H16 red and H17 green. Power on self-test: If both lights are on at the same time, it means reset. If H16 lights up and H17 goes out, it means device testing. If both lights are on at the same time, it means testing is complete and the bus is ready. Diagnostic status: When both lights are on simultaneously, it indicates that the bus is ready but there is no cyclic data exchange; H16 off and H17 on indicate that the bus is ready and data exchange is in a loop; H16 is on and H17 is flashing, indicating that PROFINET software is being loaded from the drive memory; H16 is turned off, H17 is lit with a short interrupt indicating RT Class 1 cyclic data exchange. The green LED on the RJ45 socket indicates Link/Activity (off=no connection, on=connected but no data, flashing=data exchange), and the yellow LED indicates RUN (off=initialization, flashing=Pre Operational, single flashing=Safe Operational, on=Operational).