In my programm it works like this with 6031e and 6024e and 6030e, Delphi + 7.1 or 7.2 Traditional
both counters:
Status := GPCTR_Watch(Device, ulGpctrNum, ND_COUNT,p_Count0);
Status := GPCTR_Watch(Device, ulGpctrNum1, ND_COUNT,p_Count1);
// sx:= inttostr(ulcount0)+#13#10+inttostr(ulcount1);
ulCount0 :=0;
ulcount1:=0;
Status := GPCTR_Control(Device, ulGpctrNum1, ND_RESET);
Status := GPCTR_Set_Application(Device, ulGpctrNum1,ND_SIMPLE_EVENT_CNT);
Status := GPCTR_Change_Parameter(Device, ulGpctrNum1, ND_SOURCE,ctr_s);
Status := GPCTR_Change_Parameter(Device, ulGpctrNum1,ND_INITIAL_COUNT,ulCount1);
Status := GPCTR_Control(Device, ulGpctrNum, ND_RESET
);
Status := GPCTR_Set_Application(Device, ulGpctrNum,ND_SIMPLE_EVENT_CNT);
Status := GPCTR_Change_Parameter(Device, ulGpctrNum, ND_SOURCE,ctr_s);
Status := GPCTR_Change_Parameter(Device, ulGpctrNum,ND_INITIAL_COUNT,ulCount1);
// Start
Status := GPCTR_Control(Device, ulGpctrNum1, ND_PROGRAM);
Status := GPCTR_Control(Device, ulGpctrNum, ND_PROGRAM);