What is the difference between dual and single speed?

The HI 2151/30WC,  HI2110WI, HI 3010, HI 4050, HI 4060, HI6300, HI 6310 and HI 3030 controllers have communication capabilities to send the current weight to a PLC or DCS.  The HI 17xx series communicate directly to the PLC back plane and send current weight readings to the PLC processor.

In standalone systems, you use relays and input signals. The HI 2151/30WC uses relays and set point targets and preact levels to control product flow. The HI 3030 and the HI 3010 use relays to control product flow and have the added advantage of having inputs and logic to better control the process. The HI 4050 does not have "C" form relays, but can utilize communications into a PLC or the -DIO option to control 5-24vdc relay logic and logic inputs.  The HI4060 has five A form mechanical relays and are pre-programed for rate control functions.

Single speed operation only uses one fill relay output to control a product control system.

Dual speed systems use two different material feed speeds, using two relays.

In the HI 2151/30WC when set point levels are reached a relay changes state. This in turn enables and disables control systems. Using relay logic the correct action can be achieved.

In the HI 3010 the relays can be defined to operate one after the other (sequential) or both on at the same time (simultaneous). The relay outputs will need to be defined in mapping as slow and fast feed. A slow feed is used in a single speed operation referred as a fast feed or bulk feed operation. Both slow feed and fast feed outputs must be defined in mapping when using dual speed. Using preset and automatic feed points allows the system to fill using the fast feed for as long as possible and then enable the slow feed relay to add that last small amount. The settings involve Target preact setting, automatic or manual for the slow feed starting point, and auto fast adjust manual or auto.

Target preact is set to stop operation a specific amount from the target weight. A ten pound target with a preact of one will stop the feed operation when it has reached nine pounds. That one pound would be for in flight materials and valve closure time. With HI 3010 auto preact on, this preact amount would be adjusted automatically with change in flow.

The fast weight target is also the amount of pounds from the fast target weight to shutoff. HI 3010 auto fast adjust will fine tune this target offset to compensate for changes in flow.

Using the PLC to control the relays and feeders will allow all types of fill combinations for optimum filling applications.