Swing device for moving a blood bag and method for operating a swing device

A method for operating a swing device for moving a blood bag, comprising:

• moving a tray for receiving the blood bag with respect to a stand by controlling, using a control device, an electromotive drive device operatively coupled to the tray for causing a rocking movement of the tray with respect to the stand, the drive device comprising a rotatable shaft member rotatable for driving said rocking movement of the tray,
• encoding a rotary position of the rotatable shaft member of the drive device using a position encoding device of the drive device, and
• determining, using the control device, a position of the tray with respect to the stand based on an encoder value indicative of the rotary position of the rotatable shaft member;
• wherein the position encoding device is configured to output a signal indicative of positional increments in the rotary position of the rotatable shaft member.

A swing device for moving a blood bag, comprising:

• a stand,
• a tray for receiving the blood bag, the tray being pivotable with respect to the stand,
• an electromotive drive device operatively coupled to the tray for causing a rocking movement of the tray with respect to the stand, the drive device comprising a rotatable shaft member which is rotatable for driving said rocking movement of the tray, and
• a control device for controlling operation of the drive device,
• wherein the drive device further comprises a position encoding device configured to encode a rotary position of the rotatable shaft member of the drive device, and wherein the control device is configured to determine a position of the tray with respect to the stand based on an encoder value indicative of the rotary position of the rotatable shaft member;
• and
• wherein the control device is configured to determine, in a calibration process prior to operation of the swing device for moving a blood bag, at least one reference position by controlling the drive device to cause a rocking movement of the tray and by acquiring, during the rocking movement, values of a characteristic motor parameter to define said at least one reference position based on the values of the characteristic motor parameter.