Totalization The totalization function is based on the internal rate (mass per unit time) signal proportional to belt speed and load on the associated belt scale. It is not affected by the damping function (P080). The rate signal is sampled several times a second to accurately count the mass of material conveyed. The count is held in the master totalizer used to increment the internal totalizers and to produce a pulse signal for the remote totalizers. Operation The BW100 provides four separate totalizer functions:
• internal totalizer 1 • internal totalizer 2 • remote totalizer 1 • remote totalizer 2 To avoid totalizing material at low flow rates, the totalizer drop out limit (P619) is set to a percentage of the design rate. Below this limit, totalization stops. When material flow returns to a rate above the drop out limit, totalization resumes. Totalizer resolution or count value is set by the respective control parameters, P631 -- P639. If the resolution selected causes the totalizer to lag behind the count rate, an E2 error is displayed after making the parameter entry. The error is rectified by selecting a greater resolution value. Example: Internal totalizer 1 Given: P005 = 1 (t/h) P631 = 4 Then:
totalizer count increments by 10 for each 10 metric tonnes registered External totalizer 1 Given: P005 = 1 (t/h) P638 = 5 Then: contact closure occurs once for every 10 metric tonnes registered For remote totalization, the contact closure duration is set by the respective control parameters, P643 and P644. The value is automatically calculated upon entry of the design rate (P011) and remote totalizer parameters (P638 and P639), so that the duration of contact closure allows the relay response to track the total up to the design rate. The value can be changed to suit specific contact closure requirements, such as in the case of programmable logic controllers.
If an E2 error is displayed, P638 or P639 has to be increased. The totalizers are reset through the master reset (P999), the totalizer reset (P648) or through the keypad. • master reset: the reset of all totalizer functions is included in the master reset. • totalizer reset: totalizer reset can be used to resets internal totalizers 1 and 2, or totalizer 2 independently. • keypad: pressing simultaneously while in the RUN mode resets internal totalizer 1, as well as the internal counts for both remote totalizers. 7ML19985DJ01 Milltronics BW100 - INSTRUCTION MANUAL Page 45