Networked motorized drive roller conveyor

A motorized drive roller conveyor comprising:

• one or more cards, each card configured to control an upstream zone and a downstream zone, each zone comprising a motorized drive roller assembly and a sensor configured to detect items on the conveyor,
• wherein each card is configured to measure a gap between a first item and a second item positioned consecutively on the conveyor by beginning a counter when a trailing edge of the first item passes the sensor and stopping the counter when a leading edge of the second item passes the sensor to generate a counter value indicating a length of the gap.

The motorized drive roller conveyor of claim 1, wherein the one or more cards comprises a plurality of networked cards.

The motorized drive roller conveyor of claim 1, wherein the gap is measured by counting the rotations of a drive roller.

The motorized drive roller conveyor of claim 1 wherein, responsive to the first item being stopped, the card is configured to advance the second item a distance derived from the counter value.

The motorized drive roller conveyor of claim 4, wherein the distance is equal to the length of the gap in order to eliminate the gap.

The motorized drive roller conveyor of claim 4, wherein the distance is less than the length of the gap in order to adjust the length of the gap to a predetermined length.

The motorized drive roller conveyor of claim 6, wherein the card is further configured to receive user input to define the predetermined length.

The motorized drive roller conveyor of claim 1, wherein each card is further configured to:

• stop the counter when the first item is stopped in the downstream zone, prior to the leading edge of the second item passing the sensor, to generate the counter value;
• and
• cause the motorized drive roller assembly of the upstream zone to advance the second item a distance derived from the counter value.

A motorized drive roller conveyor comprising:

• a first zone and a second zone downstream of the first zone, each zone including a drive roller and a sensor;
• and
• a card comprising a first driver that controls the first zone and a second driver that controls the second zone, the card configured to measure a gap between a first item and a second item positioned consecutively on the conveyor by beginning a counter when a trailing edge of the first item passes the sensor and stopping the counter when a leading edge of the second item passes the sensor to generate a counter value indicating a length of the gap.

The motorized drive roller conveyor of claim 9, wherein responsive to the first item being stopped, the card is configured to advance the second item a distance derived from the counter value.

The motorized drive roller conveyor of claim 10, wherein the distance is equal to the length of the gap in order to eliminate the gap.

The motorized drive roller conveyor of claim 10, wherein the distance is less than the length of the gap in order to adjust the length of the gap to a predetermined length.

The motorized drive roller conveyor of claim 12, wherein the card is further configured to receive user input to define the predetermined length.

The motorized drive roller conveyor of claim 9, wherein the card is further configured to:

• stop the counter when the first item is stopped in the downstream zone, prior to the leading edge of the second item passing the sensor, to generate the counter value;
• and
• cause the motorized drive roller assembly of the upstream zone to advance the second item a distance derived from the counter value.

The method of claim 15, further comprising advancing the second item on the conveyor by a distance derived from the counter value.

The method of claim 16, wherein the distance is equal to the length of the gap in order to eliminate the gap.

The method of claim 16, wherein the distance is less than the length of the gap in order to adjust the length of the gap to a predetermined length.

The method of claim 18, further comprising receiving user input to define the predetermined length.

The method of claim 15, wherein the method is implemented using a networked card.