I am having a communications issue. The Beckhoff is the Master and the Rexroth card is the slave. I am getting a clock signal from the Beckhoff, but the clock signal looks mirror imaged instead of offset when you compare the positive and negative on an Oscilloscope. The Rexroth card transmits no data back at all. When you send the current clock signal to it. Without this position signal the press won't run and the beckhoff just errors out. Any help would be appreciated.