Solution:

The VESRxxx and VESP211-232 boxes will have the RTS line set high, ( plus voltage state). This status does not change when a VComm port is opened, or when a Socket connection is opened. The older models, ESP211, ESP90x, and ESR90x work differently. They set the RTS line in a negative state, and when a Vcom or Socket connection is opened, it goes to a plus state. Then goes back to a negative voltage state, when the socket is closed. This may cause the newer VESxxxx units to behave differently than the older units, depending on what the end equipment is looking for.