System having combinable transmission and implement circuits

A machine, comprising:

• a frame;
• an engine mounted to the frame;
• a traction device configured to support the frame and propel the machine;
• an implement pivotally connected to the frame;
• a closed-loop, meterless hydraulic circuit having a first pump driven by the engine to pressurize fluid, and a first actuator fluidly connected to the first pump;
• a closed-loop, metered hydraulic circuit having a second pump driven by the engine to pressurize fluid, a second actuator configured to move the implement, and at least one metering valve fluidly disposed between the second pump and the second actuator;
• a combiner valve configured to selectively direct fluid from the closed-loop, metered hydraulic circuit to the closed-loop, meterless hydraulic circuit;
• at least one boost pump configured to provide feed to the second pump;
• at least one input device configured to receive input indicative of a desire to actively operate the closed-loop, meterless hydraulic circuit and the closed-loop, metered hydraulic circuit;
• and
• a controller in communication with the at least one input device and the combiner valve, wherein, when input is received indicative of a desire to transition between active operation of only the first actuator to simultaneous operation of both the first and second actuators, the controller is configured to simultaneously destroke the second pump, close the combiner valve, and decrease a displacement of the first actuator.

A method of operating a hydraulic system, comprising:

• circulating fluid from a first pump to a first actuator in a closed-loop, meterless manner;
• circulating fluid from a second pump to a second actuator in a closed loop, metered manner;
• selectively directing fluid from the second pump to the first actuator;
• wherein, during active operation of only the second actuator, the method further includes:
• inhibiting fluid from the second pump from flowing to the first actuator;
• and
• destroking the first pump;
• wherein, upon receiving input indicative of a desire to transition from active operation of only the first actuator to active operation of both the first and second actuators, the method further includes;
• responsively and simultaneously destroking the second pump, inhibiting fluid from the second pump from flowing to the first actuator, and decreasing a displacement of the first actuator;
• and
• once the second pump is at zero displacement during transition from operation of only the first actuator to operation of both the first and second actuators, the method further includes:
• metering fluid to the second actuator;
• and
• increasing a displacement of the second pump.