(5)  
The ERASE button is used to erase data that has been previously stored in non-volatile memory. This includes both manually and automatically stored data. Only the page currently displayed will be erased.

 (6)  
The TEST button is used to initiate the BITE self-test routine. When pressed, BITE signals are processed through the system and a test pattern is displayed on the top and bottom display units. When the BITE routine is finished, EICAS will display TEST OK or TEST FAIL. Any EICAS failure messages for BITE-detected LRU faults will be displayed at this time. When TEST is pressed a second time, EICAS will return to its normal mode.

  ú

 31-41-00
 ALL  ú ú 09 Page 8 ú Mar 20/92

A

757
MAINTENANCE MANUAL

 H.  GUN 102, 103; ARINC 429 Data Tap
 (1)  An ARINC 429 data tap is installed between the EICAS computer and the DFDAU. The data tap is located on a test connector in the P61 panel. The EICAS output data is sent to the DFDAU and the test connector. The EICAS data that is sent to the test connector can be collected by other equipment.
 I.  EICAS Display Pages
 (1)  Engine Primary Parameters (Fig. 3)
 (a)  
The primary engine page is shown on the top EICAS display unit. Engine parameters shown on this page are only those that are required to set and monitor engine thrust. These parameters are displayed continuously in both an analog round dial and a digital readout for both left and right engines. The primary engine parameters shown are Engine Pressure Ratio (EPR), N1, and Exhaust Gas Temperature (EGT).

 (b)  
EPR Indicators

 1)  Actual engine thrust, as measured by engine sensors, is indicated both by an actual thrust pointer and by digital readout. Any momentary difference between actual thrust and commanded thrust is shown by the command sector. The maximum thrust limit is shown by an amber marker on the analog scale. The EEC is the primary source for maximum thrust limit display; the TMC is the secondary source.
 2)  Target thrust is shown by both a reference cursor on the analog scale and a digital readout above the actual thrust readout. Thrust mode readout and derate temperature readout, if selected, are shown above the thrust indicators.
 3)  Also shown above the thrust indicators are readouts for Total Air Temperature (TAT) and thrust reverser status. If a thrust reverser is fully deployed, the readout will be green. If in transit, the readout will be yellow. For normal in-flight mode position, the readout will be blank.
 (c)  N1 Indicators
 1)  The low compressor rotor speed is indicated by both an actual N1 pointer and by digital readout. The maximum N1 rpm exceedance reached is shown beneath the actual N1 readout.
  ú