BRUEL & KJAER 1618 - Page 42

codes. The S in line 130 prevents the 5 digits from being followed by a CR (Carriage Re-
turn) code which would otherwise cause a false control setting . The data string must al-
ways contain 5 digits .
!
If, when all controls have been set, it is desired to alter only the band numbers (filter
center frequency), the following procedure should be followed to set a control and shift
frequency only :
100 PRINT "Input Codes (5 DIGITS):";
110 INPUT A
1 20 PRINT @ 3: USING 1 30
130 IMAGE 50, S
140 PRINT "INPUT CODES (2 DIGITS): ";
150 INPUT B
1
60 PRINT @ 3: USING 1 70
170 IMAGE 20, S
180 GO TO 140
190 END
Input A sets all controls, using 5 digits, after which only the band number is changed us-
ing 2 digits .
Lines
140 and 170 may be changed to:
140 PRINT "STEP USING CODE '8 ':"
170 IMAGE1D,S
Now the band number will be stepped 1 step upwards each time an 8 is entered via the
keyboard.
As with the HP-9825A, the Tektronix 4051 is unable to sense BUSY without blocking
the interface bus until the BUSY condition has disappeared. The Tektronix 4051 cannot
send the addressed command GTL, and its way of exercising REN is somewhat cumber-
some. Therefore, the example given for the HP - 9825A has no reasonable counterpart
for the Tektronix 4051.
The Tektronix 4051 has no capability for control of a Parallel Poll.
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