I. Functional Description
A single width CAMAC module has been designed and developed
at NAL for the purpose of converting either NIM type input Signals
to TTL output signals or TTL type input signals to NIM output
signals. Functionally, there are four (4) NIM inputs, four (4)
associated TTL outputs', four (4) TTL inputs, and four (4) associated
NIM outputs available at LEMO connectors mounted to the modules'
front panel. In addition', the NIM output pulses may also be
generated in response to CAMAC dataway commands. The width of
these CAMAC generated NIM output pulses may be varied by changing
the values of internal timing capacitors.
A polarity switch, mounted on the side of the modules, allows
the-user to select the pulse transition relationship between each
input and converted output pulse. A front panel. LED is used to
indicate the status of the polarity switch for each output.
II. Operational Description
A. NIM Input - TTL Output
The NIM input LEMO connectors are terminated into 50 ohms
within the module. Using the NIM Standard #TID-20893 (Rev. 3),
the input will respond to a signal which has the following values:
Logic"1" -12 to -36mA (-0.6 to -1.8 volts)
Logic "0" -4 to +2OmA (-0.2 to +1.0 volts)
The associated TTL output. will respond to the NIM input signal
with an output level which has been defined as follows:
Logic "O" >+3.5 @ 250uA
Logic "l" <+.4 volts @ 50mA
it should be noted that the output pulse will be logically
the same as the input pulse with the polarity switch in the non-
invert position. If the polarity switch is in the invert position,
the TTL output will be the logical complement of the NIM input.
The NIM input pulse shall be at least lOnSec in width and
have a maximum operating frequency of 30 Mhz.
B. TTL Input - NIM Output
The TTL Input LEMO connectors are not terminated and have
the following input cliaracteristics:
Logic "O" >+2.5 volts @ 40 uAmps
Logic "1" <+.7 volts @ 1.6mAmps
The associated NIM output will respond to the. TTL input
signal with an output level, terminated into an external 50 ohm
load, which has been defined as follows:
Logic "1" -14 to -18mA (-0.7 to -0.9 volts)
Logic "O" -1 to +1mA (-50 to +50 volts)
It should be noted that the output pulse will be logically
the same as the input pulse with the polarity switch in the non-
invert position; the NIM output pulse will be the logical complement
of the TTL input.
The TTL i nput pulse shall be at least 10 nSec in width and
have a maximum operating frequency of 3OMHz.
C. CAMAC Command - NIM Output
A NIM output pulse may be generated as a response to a CAMAC
dataway command. The width of the NIM output pulse is normally
set for 200 nsec duration as determined by an internal timing
capacitors. The duration of this output pulse may be varied by
physically changing the value of this internal timing capacitor.
If the polarity switch is in the non-invert position, the generation
of a CAMAC dataway command will cause a logical "1" NIM output
pulse to occur (as defined in section B) . The CAMAC dataway
command that will cause the NIM output pulses are defined as follows:
Data%.iay Command NIM Output
F(25)-A(O)-S1 1
F(25)-A(1)-S1 2
F (25) -A (2) -S1 3
F(25) -A(3) -S1 4
F (25) -A (4) - S1 1-4
An X and Q response are generated for each of the above valid
dataway, commands.
III. Front Panel Identification
In
The identification of the connectors and
LED's follows:
A. NIM to TTL
(4) NIM Input LEMO connectors (Numbered 1-4)
(4) TTL Output LEMO connectors (Numbered 1-4)
(4) Output Polarity Status LED'S.
B. TTL to NIM
(4) TTL Input LEMO connectors (Numbered 1-4)
(4) NIM Output LEMO connectors (Numbered 1-4)
(4) Output Polarity Status LED'S.
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