Agilent Technologies 6625A, 6626A, 6628A Service Request and Serial Poll, Enable Intr, OFF Intr

Service Request and Serial Poll

The fault and mask registers, when used in conjunction with the service request and serial poll functions, allow you to select which conditions can cause computer interrupts. The fault and mask registers can also be used independently of the serial poll or service request if so desired. The following example shows how to enable an interrupt to the computer in the case of an overvoltage condition. After the interrupt has occurred, this example includes an interrupt routine that conducts a serial poll to determine on which output the overvoltage occurred. Note that this example assumes that terminal block external OV trip lines are not wired together.

10 ASSIGN @Ps TO 705

20 COM /Ps/ @Ps

30 OUTPUT @Ps;’’CLR;UNMASK1,8;UNMASK2,8;SRQ1’’

40 ON INTR 7,1 CALL Err _ trap

50 ENABLE INTR 7;2

60 OUTPUT @Ps;"OVSET1,4;OVSET2,4"

70 OUTPUT @Ps;’’VSET1,5;VSET2,5"

80 Lbl: GOTO Lbl

90END

100!

110!

120SUB Err _ trap

130OFF INTR

140COM /Ps/ @Ps

150IF BIT(SPOLL(@Ps),0) THEN

160OUTPUT @Ps;’’OUT1,0;OVRST1"

170PRINT "OVERVOLTAGE ON OUTPUT #1"

180END IF

190IF BIT(SPOLL(@Ps),1) THEN

200OUTPUT @Ps;"OUT2,0;OVRST2’’

210PRINT ’’OVERVOLTAGE ON OUTPUT #2"

220END IF

230OUTPUT @Ps;’’FAULT?1;FAULT?2’’

240SUBEND

LINE 10: Assigns the I/O pathname to the power supply.

LINE 20: Declares a common block for the I/O pathname. The COM statement must be used for the @Ps variable to preserve its value for use in the service routine.

LINE 30: Returns the power supply to its power on state, unmasks output 1’s and output 2’s OV status bits to generate faults, and enables the service request capability on all outputs.

LINE 40: Defines interrupt at interface 7, with GP-IB priority 1.

LINE 50: Enables interrupt at interface 7 for service request type interrupts only.

LINE 60: Sets the overvoltage of outputs 1 and 2 to 4 volts.

LINE 70: Sets the voltage of outputs 1 and 2 above the OV setting so that both outputs will overvoltage when the program is run.

LINE 80: Waits for the computer to receive the interrupt. This simulates conditions that would normally exist when a program is running.

LINE 120: Defines the error handling routine.

LINE 130: Disables interrupt capability while processing.

LINE 140: Brings in the common block for the I/O pathname.

LINE 150-180: Conducts a serial poll. If bit 0 in serial poll register indicates a fault for output 1, output 1 is disabled and the overvoltage circuit is reset.

LINE 190-220: Checks bit 1 in serial poll register for a fault on output 2. If true, output 2 is disabled and the overvoltage circuit is reset.

LINE 230: Reads fault registers to clear FAU bits in serial poll register.

106Programming with a Series 200/300 Computer