Caen V895 Series, Manual, Page: 18 / 25

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User's Manual (MUT) Mod. V895 16 Channel Leading Edge Discriminator 19/03/09 3
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3.2. Discriminator thresholds
(Base a %00 to %1E write only)
These registers contain the discriminator thresholds values on 8 bit words. The
thresholds values can be programmed in a range from -1 mV to -255 mV with 1 mV
steps, writing an integer number between 1 and 255 into the register; the thresholds are
individually settable.
3.3. Pattern of inhibit
(Base a %4A write only)
This register contains the Pattern of Inhibit, a 16 bit word indicating which channels are
either enabled or disabled (bit X=1
⇒
Ch. X enabled…bitX=0
⇒
Ch. X disabled).
3.4. Output width Ch. 0÷7
(Base a %40 write only)
This register contains the output pulse width value of the channels 0 through 7 on a 8 bit
word. This value can be adjusted in the range from 5 ns to 40 ns, writing an integer
number between 0 and 255 into the register. The set value corresponds to the width as
follows: 255 leads to a 40 ns pulse duration, 0 leads to a 5 ns pulse duration, with a
non-linear relation for intermediate values
3.5. Output width Ch. 8÷15
(Base a %42 write only)
This register contains the output pulse width value of the channels 8 through 15 on a 8
bit word. This value can be adjusted in the range from 5 ns to 40 ns, writing an integer
number between 0 and 255 into the register. The set value corresponds to the width as
follows: 255 leads to a 40 ns pulse duration, 0 leads to a 5 ns pulse duration, with a
non-linear relation for intermediate values
3.6. Majority threshold
(Base a %48 write only)
This register allows to set the Majority threshold between 1 and 16 for Internal Majority
and between 1 and 20 for External Majority writing a proper value in the Base address
+ %48 (value range: 1÷244).
The Majority threshold can be calculated in the following way:
MAJTHR = NINT[(MAJLEV*50
−
25)/4] ,
where NINT is the nearest integer function (allowed values for MAJLEV: 1 to 20) e.g.: if
the desired Majority level is 5, the correct MAJTHR value to use is 56 (see also § 4.7).