Timing Signals

Timing signals (10kHz) for the DSP can be generated either by a Timing Board or an ADC Board.

Timing Signals from a Timing Board

In this case you need a TIM board installed together with a RIO that runs a Galaxy Server. That server configures the TIM board, reads out the timing signals and writes also some time information directly into the DSP dual-port memory.

To propagate the time signal to the ADCs and DACs you have to connect the corresponding output of the TIM board (usually Out4?) with the SYNC inputs of the ADC and DAC boards. Also you have to remove the jumper of all the involved ADC boards, because this jumper is used to configure the internal time signal generation. On the other hand, the jumper on the DAC board is a 50-Ohm terminator. In case of external signals the time propagation chain has to be finished by a 50-Ohm terminator, meaning that if you have several DACs only one board should have the jumper set, and the time signal chain has to finish at that board. If you do not have DACs you can use a Twin-connector with a 50-Ohm terminator at the last ADC.

To set the ADCs and DACs correctly you have to use the tools available at Sa/ServerDamping/<version>/RIO806X/:

• dspinfo.exe
• dspad.exe
• dspmap.exe
  

Also you have to set correctly the EServerDSP configuration files:

• check with dbui: Sa/ESDSP/Config, localTime should be set to "0".
• /virgoData/Sa/Damping/setup.dat: the corresponding entry contains a keyword "adc" that should be set to "0" for external time signals, and to "1" for internal time signal generation.
  

Check that the LED "Master" (indicates internal signal generation) of the ADC is off.

Timing Signals from an ADC Board

In this case you do not need the TIM board and the RIO. Set the jumper of one ADC board and connect the time signal chain to the corresponding SYNC inputs of the other ADC and DAC boards. Make sure that the chain is finished by a 50-Ohm connector. Check also the EServerDSP configuration files. The ADC LED "Master" should be on.

ADC and DAC Boards in Standalone

TBD