Batch controllers are available in two basic configurations. The Model B2 controller is engineered to provide control of the number of cycles produced by a solenoid-controlled AODD pump in a “Batch”. This handheld unit is locally controlled and programmed for individual batching and dispensing operations. The Model 420 controller is engineered to provide speed control of a solenoid-controlled pump that is linearly proportional to an external 4-20 ma signal. Both controllers should be used with our 12VDC solenoids.solenoids are available in 12VDC, 24VDC, 120VAC or 220VAC and utilize a standard DIN 43650B or DIN 43640C connector, depending on the pump size. In addition to solenoid control, cycle counters are available on all pumps.