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CA008

Connection of FAST ADC 7072/7072T to MPA-3 or MPA-2

Due to a bug in the firmware of 7072 / 7072T ADCs delivered before Q2/2003, the ENC gating in coincidence mode of the MPA-3 disables the slider in the ADC. This results in strong modulations of spectra with periodicities of 8 and 16 channels. As a quick work-around an ADC cable as shown here may be used. This uses the DENB line that can be set by software to set the ADC ENC permanently to high. Use a "polarity" value of 15 in the mpa3.ini file for the respective ADC. For users of the older MPA/PC (MPA-2) system with MPAWIN software: The corresponding line in the MP.POL file is
1 0 1 1 0 0 0 0

For SPA-3 users: The issue arises only if using the Reject input and if listmode is disabled by setting listver=0 in the spa3.ini file. In this case use this connector and a value polarity=15 for the respective ADC in the SPA3.INI file.


Since March 17, 2003 we have a new firmware for the ADC 7072/7072T that fixes all presently known bugs. If you have such an ADC delivered before, please contact your vendor to send back your ADC to FAST ComTec