Modbus Data Acquisition.
The DAT9000 and DAT9011 Modbus Masters and Modbus Slaves range of controllers have Ethernet, RS485, RS232 and USB ports. Options on these units have on board digital and analog IO and the DAT9011DL has data logging capability that logs data from not only it's own inputs but the DAT3000 series and other connected slaves from other manufacturers. The data is logged to the USB port which is situated on the front face of the DAT9011DL and can take an 8G USB thumb drive.
The digital input can be voltage and the output can be selected from relays, NPN or PNP transistor outputs.