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43.1 GENERAL DESCRIPTION . . . . . . . . . . . . . . 43-1
43.2 CAMAC COMMAND SUMMARY . . . . . . . . . . . . . 43-2
43.2.1 F16-A(0) loads the enable register for channels
43.2.2 F16-(A1) loads the enable register for channels
43.2.3 F16-A(2) loads the 'CONTROL' register . . . . 43-2
43.3 CALIBRATION . . . . . . . . . . . . . . . . . . 43-3
43.4 DRAWING PACKAGE NUMBER . . . . . . . . . . . . . 43-3
43.5 RESPONSIBLE ENGINEER . . . . . . . . . . . . . . 43-3 CHAPTER 43 SAM TESTER
43.1 GENERAL DESCRIPTION The SAM Tester is a single width CAMAC module used as an aid in testing the Smart Analog Monitor (SAM) 123-603. This unit is intended to be used for the functional checkout of the SAM or in conjunction with a DVM for absolute accuracy tests. The functional checkout consists of applying a bipolar voltage to any number of channels on either differential leg of the SAM inputs. This tests channel to channel cross talk and the integrity of each analog input to the SAM. The voltage accuracy in this mode is better than 1% of full scale over three decades after the tester has been calibrated. The accuracy tests require that a DVM be interfaced to a common computer with the SAM and SAM Tester, and has accuracy specifications much better than the SAM. A thirty-third channel is provided via a dual lemo receptacle on the front panel (J4) for this purpose. Two thirty-six pin Amp connectors are provided on the front panel, P2 and P3, to interface directly all thirty-two channels of the tester to the SAM. The SAM Tester consists of three major functional blocks. The first is a twelve bit bipolar DAC loaded by F16-A3. The values are true binary, where 0 equals minus full scale, '800'X equals zero volts, and 'FFF'X equals positive full scale. The second stage is a three step attenuator. The 'CONTROL' register loaded with F16-A2, controls the attenuator and two other functions that will be discussed later. W1=1 selects the 0.1 volt range, W2=1 selects the 1 volt range, and W3=1 sets the 10 volt range. The two other CONTROL register bits are polarity control and reference enable for the DVM. The polarity control is provided to exercise both legs of the differential inputs. In positive mode, F16-A2: W4=0, the normal negative input is grounded and the bipolar voltage is applied to the positive input. Conversely, in the minus mode, W4=1, the normal positive terminal is grounded and the negative terminal will have the voltage applied. Note: in the negative mode the DAC voltages will appear inverted. The reference control enables the DAC voltage the DVM, (F16-A2;W5=1), or a ground reference, W5=0. The analog output control is the final stage of SAM Tester. Two sixteen-bit registers are used to enable each individual channel. This is provided to check for channel to channel voltage breakdown and to test for channels that may be shorted together. The unselected channels are grounded. F16-A0 selects channels 0 through 15 and
SAM TESTER Page 43-2 F16-A1 selects 16 through 31. W1 enables channel 0 or 16 and W16 selects channel 15 and 31.
43.2 CAMAC COMMAND SUMMARY
43.2.1 F16-A(0) loads the enable register for channels 0-15. o W1 through W16 selects channels 0 to 15. o A logic one applies the DAC voltage and a logic zero grounds the input.
43.2.2 F16-(A1) loads the enable register for channels 16-31. o W1 through W16 selects channels 16 to 31. o A logic one applies the DAC voltage and a logic zero grounds the input.
43.2.3 F16-A(2) loads the 'CONTROL' register o W1=1 sets the 0.1 volt range to the DAC. o W2=1 sets the 1 volt range. o W3=1 sets the 10 volt range. o W4=0 is the normal positive polarity select. Positive means the DAC voltage is applied to the normal plus SAM input. The other input is grounded. o W4=1 sets the negative mode. Negative mode means the DAC output is applied to the normal minus SAM input. The other input is grounded. o W5=0 sets the DVM channel to ground. o W5=1 sets the DVM channel to the DAC voltage.
SAM TESTER Page 43-3
43.3 CALIBRATION The calibration consists of adjusting the offset and gain of the three voltage ranges. Connect a DVM to J4. Select the ten volt range with normal polarity and the DVM channel enabled. Set the DAC '800'X and adjust R4, the offset trim, until zero volts is reached. Now set the DAC to 'FFF'X and adjust R9, the gain trim until 9.995 volts is read. Repeat the offset and gain adjustments until reading are within 10 milli-volts of setting. Repeat the above procedure for the one volt and tenth volt ranges. R12 is the offset and R10 is the gain for the one volt range. R15 is the offset and R7 is the gain for the tenth volt range. All adjustments should be to 0.1% of full scale of the range setting.
43.4 DRAWING PACKAGE NUMBER 123-615
43.5 RESPONSIBLE ENGINEER D. J. Nelson