UDP 502
Synopsis
- UDP port 502 is used by Modbus/UDP (the UDP variant of the Modbus industrial control protocol).
- Advantech ADAM-6000 Ethernet I/O modules expose Modbus/UDP on 502 for data acquisition and control.
- ICP DAS ET-7000/PET-7000 Ethernet I/O devices support Modbus/UDP on port 502.
- Unitronics PLCs (e.g., Vision and UniStream series) can act as Modbus/UDP servers/clients on UDP/502.
- Moxa MGate Modbus gateways (e.g., MB3170/MB3270 series) support Modbus/UDP on port 502 to bridge Ethernet and serial Modbus.
- Kepware KEPServerEX includes a “Modbus UDP” driver that communicates with devices over UDP/502; CODESYS runtimes also provide Modbus UDP master/slave stacks using this port.
- Security note: Modbus provides no authentication or encryption, so UDP/502 services on ICS devices are frequently scanned and can be abused to read/write registers or coils if exposed.
Observed activity
Last 30 days
Detailed chart