To de ter mine what has caused the SRQ, the sta tus reg is ter in the power me ter
must be read. The sta tus reg is ter in the me ter is an 8-bit reg is ter. There are
two ways to do this.
a. Read the sta tus reg is ter us ing the equiv a lent of a GPIB se rial poll. Send the
mes sage:
!SPL
Note: There is NO ter mi na tor to this mes sage.
The power me ter will re spond:
Px\n
x is the ASCII char ac ter de ter mined by the value in the me ter sta tus reg is ter.
x = “B” gives a sta tus reg is ter value of 01000010 bi nary. Com paring this with
the sta tus byte de scrip tion in Sec tion 6-7 of the man ual will show that the
SRQ and lim its er ror bits are both set.
b. Al ter na tively the sta tus reg is ter can be read di rectly us ing the com mand:
*STB?\n
This will re spond:
Ry\n
y can be up to 3 dig its and is the dec i mal rep re sen ta tion of the sta tus reg is ter.
y="66" gives a sta tus reg is ter value of 01000010 bi nary. Com paring this with
the sta tus byte de scrip tion in sec tion 6-7 of the man ual will show that the SRQ
and lim its er ror bits are both set.
8. Once the sta tus reg is ter has been read, it must be cleared to al low fur ther
SRQ mes sages to be sent. Be fore the sta tus reg is ter is cleared, fur ther autodial
ac tions (lim its fail ure or sen sor range er ror) should be dis abled to pre vent any
un nec es sary autodial at tempts by the me ter when al ready con nected to a re -
mote PC. To clear the sta tus reg is ter, use the com mand:
*CLS\n
5-11 PROFILE
OPERATION MODE
The ML2400A Se ries Power Me ter can be used to view sig nals in Pro file, Read -
out, Power vs. Time and Source Sweep modes. This sec tion de scribes set ting
5-10 ML2400A OM
PROFILE OPERATION MODE PROCEDURES
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