BIT 4886 051010
4-7
mum current delivery and verifies that the voltage limit set at one volt operates correctly. It also
tests the readback voltages in both high and low scales.
CAUTION: TO AVOID DAMAGE TO THE LOAD, DISCONNECT THE LOAD BEFORE ISSU-
ING
THIS COMMAND. (DURING THE SELF-TEST, THE BOP IS PRO-
GRAMMED TO FULL SCALE POSITIVE AND FULL SCALE NEGATIVE
OUTPUT.)
This command returns a 0 for pass, or a 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.
4.4
IEEE 488 (GPIB) BUS PROTOCOL
Table 4-2 defines the interface capabilities of the Interface Card (Talker/Listener) relative to the
IEEE 488 (GPIB) bus (reference document
ANSI/IEEE Std 488: IEEE Standard Digital Interface for
Programmable Instrumentation
) communicating with a Host Computer–Controller (Talker/Lis-
tener).
Tables 4-3 and 4-4 define the messages sent to the Interface Card, or received by the Interface
Card, via the IEEE 488 bus in IEEE 488 command mode and IEEE 488 data mode, respectively.
These messages are enabled during the “handshake” cycle, with the Interface Card operating
as either a Talker or a Listener.
TABLE 4-2. IEEE 488 (GPIB) BUS INTERFACE FUNCTIONS
FUNCTION
SUBSET
SYMBOL
COMMENTS
Source Handshake
SH1
Complete Capability (Interface can receive multiline messages).
Acceptor Handshake
AH1
Complete Capability (Interface can receive multiline messages).
Talker
T6
Basic talker, serial poll, unaddress if MLA (My Listen Address) (one-byte
address).
Listener
L4
Basic listener, unaddress if MTA (My Talk Address) (one-byte address).
Service Request
SR1
Complete Capability. The interface sets the SRQ line true if there is an
enabled service request condition.
Remote/Local
RL2
No Local lock-out.
Parallel Poll
PP0
No Capability.
Device Clear
DC1
Complete Capability. Controller sends DCL (Device Clear) and SDC
(Selected Device Clear) to selected power supply.
Device Trigger
DT1
Complete Capability.
Controller
C0
No Capability.
