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2132 Interface. The HV4032 will process this data, look for errors (par-
ity), and send a Finished response on completion of the command. If the
high voltage is ON the response will occur after the voltage have been
modified. If the high voltage is OFF the response will be given upon
receipt of the data.
After the high voltage ON command is used, a delay of approximately 20
seconds allowing voltage run-up will be experienced before the finished
response will be given. (Response is generated when the microproces-
sor is no longer "busy".) The user should modify his software for his
convenience so that considerable computing time is not lost in waiting for
this response. (Figure 9).
In generating commands to the HV4032 via the 2132 CAMAC Interface,
care should be exercised in writing into the FIFO 2 (Figure 3). Though
the buffer is 40 words deep it must be realized that the buffer data is
transferred to the HV4032 at a much slower rate than the CAMAC
dataway can write. Do not attempt to write more than 40 words at one
time.
If several commands are to be given, i.e., modify 32 channels for more
than one mainframe, wait for a response from the first mainframe before
addressing the next.
A module zero address can be used to address all mainframes in a daisy
chain. Never use this command where a response totaling more than 40
words will occur. For example, requesting 32 ADC voltages from all
mainframes.
Error detection is performed by decoding the 16-bit response words. The
lower order four bits will define the nature of the error, (i.e., 12 = parity,
13 = overwrite). A parity error implies a command to an HV4032 which
was not recognized. This can be generated by any unit in a daisy chain
as all units will see the command from the 2132, but only the HV4032
recognizing the address should respond to the command given.
Each of the three characters in a word has a parity bit which is checked
before the data is processed. If a parity error is detected, the command
will be aborted and the user will have to re-initiate the command.
An overwrite error will occur should a second character arrive before the
first character is processed. The likelihood of this occurring is very small
since the timing is controlled by hardware in the 2132 Interface. In the
event that an overwrite error is detected, the command will be aborted
and will necessitate re-initialization of the command as above. Both
overwrite and parity are errors detected at the HV4032.
Transmission error is detected at the 2132 and includes either parity or
overwrite error of a response.
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