I'm thinking of trying to communicate information (counters, data integers/v memory) from a directlogic PLC to an allen bradley slc504. my question is would ethernet be the best way and any tips on if it's even compatible to do.
The SLC 5/04 CPU family does not support Ethernet communications; only the latest, SLC 5/05 series, allows it.
Since the AutomationDirect PLCs provide only Ethernet and Serial communications options I guess you will probably have to run Modbus RTU on a RS-232/422 network; for the SLC 5/04 end you will need a communications module such as the ProSoft MVI46-MCM (http://www.prosoft-technology.com/content/view/full/135)
On the DL side, if wanting to establish a peer-to-peer connection you might need a supplementary communications module; otherwise, most of the DirectLogic CPUs on-board communications ports could communicate as a slave Modbus RTU node.