HL7ServerIP = dt(0)("ServerIP").ToString();
HL7SendPort = dt(0)("SendPort").ToString.Trim;
TempLogFolder = dt(0)("TempLogFolder").ToString.Trim;
StopSendPort = Module1.CheckNullIntegerToBoolean(dt(0)("StopSendPort"));
Try box brackets instead -
HL7ServerIP = dt[0]["ServerIP"].ToString();
HL7SendPort = dt[0]["SendPort"].ToString.Trim;
TempLogFolder = dt[0]["TempLogFolder"].ToString.Trim;