4-6
BIT 4886 051010
4.3
BUILT IN TEST
The BIT 4886 card is designed to perform periodic testing of itself, power up testing and com-
manded testing. The testing is reported to the operator both by errors placed in the SCPI error
queue and by issuing audible beeps.
The driver and demonstration soft panel which can be downloaded from the Kepco website at:
www.kepcopower.com/drivers.htm provide an easy way to verify BIT 4886 performance. A
description of the driver is included as an Adobe Acrobat ™ PDF file.
4.3.1
POWER-UP TEST
The power up testing of the BIT 4886 is similar to the *TST command (PAR. A.17). Portions of
the card are verified on power-up and errors are indicated by the beep codes listed in Table 4-1.
The failed test is repeated indefinitely. The power-up test can be bypassed by placing all DIP
switch positions of address switch S1 to up (ON, 1). Once bypassed, the unit beeps on and off
at equal intervals to indicate the address switches are set to 1 and the unit is waiting for the
address switches to be set to a valid GPIB address.
4.3.2
CONFIDENCE TEST
The SCPI command *TST? Is used to perform a confidence test of the interface. It verifies the
microprocessor memory, the timer, optical buffer and reference of the BIT 4886 card. It does not
affect the output of the BOP. This command returns a 0 for pass and number from 1 through
1023 to indicate the cause of the error. The test executes each of the subtests even when any
one fails. If any test fails a bit is set in the error code which is returned to the user. The error
codes returned are listed in Table 4-1
4.3.3
BOP TEST
The DIAG:TST? Command performs a test of the BOP instrument. The test includes the BIT
4886 internal tests of the DAC (Digital to Analog Converter), Limit and Op Amp circuits. If suc-
cessful it programs the BOP in voltage mode to the positive and negative limits of the device. It
also verifies the Limit operation of the unit in current mode by setting the unit for the rated maxi-
TABLE 4-1. BUILT-IN TEST ERROR CODES
TEST ACTIVE
ERROR CODES
MEANING
*tst? DIAG:TST?
BIT
VALUE
BEEPS
Yes
Yes
0
Pass (No error)
Yes
Yes
0
1
1
ROM error
Yes
Yes
1
2
1
RAM error
Yes
Yes
2
4
2
FLASH error -- Perform calibration to correct
Yes
Yes
3
8
3
Optical Buffer Error‘
Yes
Yes
4
16
6
Digital Pot error
No
Yes
5
32
5
Loop Back Test error
No
Yes
6
64
Max Voltage Output error
No
Yes
7
128
Min Voltage Output error
No
Yes
8
256
1/4 Scale Voltage error
No
Yes
9
512
1/4 Scale Voltage Readback error
