EL1018 Wiring Diagram
You can get the wiring diagram from Beckhoff Information System or from the module itself. It is troublesome to shut down power and pull the module out just to look at its wiring diagram. I uploaded it here. Hopefully other electricians do not need to go through the same trouble as I did.
More Information:
Please visit http://www.beckhoff.com for more details.
To save yourself even more trouble, just look up the diagram on the web. All modules are easily found by typing the Beckhoff web server followed by the module ID, for example, http://www.beckhoff.com/EL1018