Instruction manual

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3.7.5.25.MESSAGE SEPARATORS
A complete message consists of a header and an argument. Since more than one message can
be sent in a setup string, message separators included in the string between the message will
make it more readable to the human operator. Three message separators are recognized: the
comma (,), semicolon (;) and a space. Since these separators are ignored, they may be
dispersed throughout a setup string.
The following are two examples of ASCII strings with separators:
PHZA90;FRQ60;AMP115
CRL,90;FRQ50;AMP,120
3.7.5.26.SERVICE REQUEST
After power-up the GPIB Service Request (SRQ) will be generated after any error (example.
syntax, output fault, etc.). This SRQ output can be inhibited by the SRQ header followed by
the single digit "0". The SRQ can be reenabled by the SRQ header followed by 1. Sending
SRQ2 causes an SRQ to be generated after the execution of a setup string or when data is
available after request of measurements. The setup string can be of any type: ramp, calibration,
etc.
The following example disables GPIB SRQ.
SRQ0
The following example will cause the SRQ to be generated when the APW measurement data
is available:
TLK APW SRQ 2
3.7.5.27.SERIAL POLL STATUS BYTE
Once the bus controller has detected the SRQ, it must determine the instrument needing
service by the Serial Poll. During the polling routine the instrument needing service will
return a Status Byte (STB) greater than decimal 63. The Status Byte values for various
faults are given in Table 3-15.