It's a non-event.
quorum call - A call of the roll to establish whether a quorum is present. If any Senator "suggests the absence of a quorum," the Presiding Officer must direct the roll to be called. Often, a quorum call is terminated by unanimous consent before completion, which permits the Senate to use the quorum call to obtain a brief delay to work out some difficulty or await a Senator's arrival.http://www.senate.gov/reference/glossary_term/quorum_call.htm
Thank you. But this one seems not to be a nonevent. Maybe it is being used to compel attendence by the Dems.
Appreciate the answer though.