Harvard Apparatus”s PHD OEM pumping module is designed for high pressure, accurate, and precise dispensing of fluid to a process or instrumentation. With the “Program” and “Auto Fill” buttons, the pump can be programed with a sequence of pumping steps. Users can start or stop the pump, change the pumping direction, change the flowrate, pump a precise volume and stop, pause the pump, and ramp up or ramp down the flowrate. The Auto Fill key is useful when the user would like to deliver a large volume of fluid. The user sets a target volume and then programs the refill volume for the syringe. The pump will automatically refill the syringe as many times as required to reach the target volume. Then the pump will automatically stop. This process does require the use of a valve. On the back side of the pump are two RS232 ports. One is for input from a computer, and the second is for output when daisy chaining more than one pump together. The I/O port is a nine-pin D sub connector and is used for TTL control. Also on the back is the universal power entry module, which encompasses the ON/OFF switch, fuse, and universal power supply. This power supply will accept power input from 110 to 240 VAC, 50/60 Hz. The mechanical stop collars cause the pump to stop automatically to protecting syringes.