LeCroy 8901A Operator's Manual page 16

Operating Instructions
Commands to an
Individual Instrument
To send a CAMAC command to a particular instrument the
GPIB controller must address the 8901A to Listen and load it
with the desired command information. If the first byte re
ceived by the interface after entering Listen mode is a valid
CAMAC function (F) code, (0 to 31) the 8901A assumes that
it is being sent a command sequence. The second byte ex
pected is the CAMAC subaddress (A) code. This is followed by
the CAMAC station number (N) code and up to three bytes of
data (least significant byte first). Once the command is sent to
the 8901A the information will be retained until modified or the
power is turned off. The GPIB system computer may terminate
the command loading procedure after any number of bytes have
been sent. In other words, if the only difference between the
last CAMAC command and the next one to be sent is the F
code, it is not necessary to send a new A, N, etc.
After loading the 8901A with the desired command, a CAMAC
cycle must be executed (by addressing the 8901A to Talk) to
send the command to the particular instrument.
PROGRAMMING
EXAMPLE
OUT x,y,...
IN bl,...bn,r
The following example illustrates the use of most of the 8901A
commands. The procedure uses the following typical sequence
of commands to control a LeCroy Model TR8837F Transient
Recorder.
Initialize the instruments upon power on
Enable LAM
Initiate sampling
Wait for trigger
Enable TR8837 for reading
Read data out in high speed mode
Read acquisition parameters
The implementation of this sequence (from the GPIB system
controller) is given below. The following notation is used:
indicates a transfer from the GPIB controller to the 8901A.
includes addressing the 8901A to Listen, sending the data
byte(s) to it, and then sending the GPIB Unlisten command.
It
indicates a n+1 byte transfer from the 8901A to the GPIB con
troller (bl ... bn are data bytes, r is the CAMAC response byte
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