Air carrier flight crew reported a low speed rejected takeoff due to improper flap setting.

Attributes
ACN	1615382
Time
Date	201902
Local Time Of Day	0601-1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Route In Use	None
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 32 Flight Crew Total 12358 Flight Crew Type 3541
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 76 Flight Crew Total 13900 Flight Crew Type 6200
Events
Anomaly	Deviation - Procedural Published Material / Policy

Narrative:

During final cockpit preparation; a significant amount of attention was paid to the [company] update for verifying performance. This resulted in not trapping an error of arming LNAV instead of our assigned heading on the MCP. That error was trapped as we were calling for taxi; unfortunately correcting that error resulted in me forgetting to call for 'flaps 10' prior to aircraft movement. During the before takeoff checklist the focus during the flaps checklist item became verifying that the fdp flaps matched the FMC setting; instead of verifying flaps 10 on the upper EICAS. The EICAS configuration warning trapped the error as the takeoff roll was started; resulting in a low speed reject. The aircraft cleared the runway; the flaps were set correctly; the takeoff runway or performance change procedure was completed; including the before takeoff checklist; and the subsequent takeoff was completed normally.

Original NASA ASRS Text

Title: Air carrier flight crew reported a low speed rejected takeoff due to improper flap setting.

Narrative: During final cockpit preparation; a significant amount of attention was paid to the [company] update for verifying performance. This resulted in not trapping an error of arming LNAV instead of our assigned heading on the MCP. That error was trapped as we were calling for taxi; unfortunately correcting that error resulted in me forgetting to call for 'Flaps 10' prior to aircraft movement. During the Before Takeoff Checklist the focus during the flaps checklist item became verifying that the FDP flaps matched the FMC setting; instead of verifying flaps 10 on the Upper EICAS. The EICAS CONFIG warning trapped the error as the takeoff roll was started; resulting in a low speed reject. The aircraft cleared the runway; the flaps were set correctly; the Takeoff Runway or Performance change procedure was completed; including the Before Takeoff checklist; and the subsequent takeoff was completed normally.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.