Enhanced Program Pumps for Multiple Step Operation

All Cronus Delta 2000 series and some Sigma series syringe pumps are available with enhanced programmability, 
as well as the Delta 4100 high pressure syringe pump. These pumps allow complex multistep dispensing direct from the pump keypad and without the need for computer control.

From the keypad, a custom program can be created which will control the syringe pump from seconds to days, permit the flowrate to be changed for specific time periods; control repeat dispensing, output TTL signals to coordinate with other laboratory instruments (or valves); or respond to inputs from other devices such as switches or relays. Complete dispense sequences can be repeated for automated operation of even quite complex applications.

The Program

A program is divided into time periods called STEPS, each of which can be up to 12 hours long. Each step is automatically numbered and a menu prompts the user to select the options available in each step which simplifies programming a lot,

The flowrate can be ramped up or down or kept constant for a defined time period for a volume dispense. The initial and final flow rate for each period is entered and the pump automatically calculates linear rate changes over the time period.without the need for ramping increments.

The syringe pump can be paused and then restarted, either by a time delay or by a TTL input. Both TTL inputs and outputs can be controlled by the pump as well. The syringe pump can therefore respond to switch closures or send out signals to actuate a valve, or other relays, switches etc.

Two separate loops can be programmed so that steps can be repeated. The number of repeat operations is controlled by the "loop count". For example, this is helpful when a switch triggers a repeat volume dispense.

The two loops can be "nested" so that the program can run for days and complex dispenses can be repeated many times.

• Each step offers these options:
• Time duration from one second up to 12 hours
• Travel direction – Infuse or withdraw (where available)
• Beginning flow rate (µl/hr to ml/min range)
• End flow rate (µl/hr to ml/min range)
• Pause – Waits for an external trigger to start
• Status of output TTL pins
• Loop option – Loops back to any previous step and repeats the intermediate steps. 
Two separate loops are available.
• Set the count in the loop cycle. Steps may be repeated up to 100 times.

An example of the result of a program can be shown graphically as below

This is a simple example but demonstrates the effects of individual steps within a program.