Board layout

Figure 2 shows the layout of the frontpanel and the locations of the switches and jumpers on the board.

The connector labeled TX connects to the optical fiber which will carry the AST data output signal.

At the bottom of the frontpanel there are 2 LEMO connectors:

• START EVENT
  is a NIM input, with which run is enabled (the AST output is started).
• END EVENT
  is a NIM output; a pulse is present on this output when the AST sends a control token.

The frontpanel has the following LEDs:

• INIT
  LED flashes when address locations WRITE_COUNTERS (counter presets are loaded into the TC and CC counters) or WRITE_FIFO (a data item is loaded into the AST FIFO) are accessed.
• RUN
  the status of run (LED on means enabled).
• EVT
  the status of event-mode (LED on means enabled).
• CIRCLE
  the status of circulate-mode (LED on means enabled).
• CONTI
  the status of continuous-mode (LED on means enabled).
• TRANSF
  LED on when data transfer from AST FIFO to on-board AORTA-T FIFO in progress.
• RESET
  LED flashes when address location RESET is accessed (a reset is given).

The on-board jumpers have the following functions (between brackets the jumper location)

• J6: A32 addressing (1) or A24 addressing (2).
• J10: START EVENT input NIM (2) or TTL (1) level.
• J13+J14: END EVENT output NIM (2) or TTL (1) level.

 
Figure 2: Frontpanel and location of on-board switches and jumpers.