Delta RMC151 - Manual (Page 92)

RMC70/150 and RMCTools User Manual
Once the virtual axis has been set up, you can issue closed-loop motion commands to it
as to any position axis.
3.3.4.4. Input Type: Pressure
Pressure input force refers to measuring pressure using a single pressure transducer. A
pressure input requires only one analog input on the RMC.
In applications using hydraulic cylinders, notice that it is not possible to calculate resultant
force on the rod with only one pressure transducer because the pressure on the other side of
the cylinder is unknown. Applications with one pressure transducer cannot use force control,
but can use pressure control. For details on measuring force on a hydraulic cylinder, see the
Input Type: Dual-Input Force topic.
3.3.4.5. Input Type: Single-Input Force
Single-input force refers to measuring force using a single transducer, typically a load cell.
Single-input force requires only one analog input on the RMC.
In applications using hydraulic cylinders, force can also be measured using dual-input force,
requiring two pressure transducers mounted on either side of the cylinder. For details, see the
Dual-Input Force topic.
3.3.4.6. Input Type: Dual-Input (Differential) Force
Dual-input force, also known as differential force, is a method of determining the force applied
by a hydraulic cylinder. As shown in the illustration below, this method requires two pressure
transducers mounted in either end of a hydraulic cylinder; one on the A port (cap end) and
another on the B port (rod end). Multiplying the measured pressure on each side of the piston
by the respective area of the piston gives the force on each side of the piston. The difference
of the absolute value of these two forces is the differential force applied to the cylinder rod.
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