TM 5-6675-320-14
Table 4-26. HP-IB ERROR DISPLAYS AND POSSIBLE CAUSES - Cont
D i s p l a y o r P r i n t o ut
Possible Causes
SERVICE REQUEST FAILURES
“INTERFACE REQUESTED SERVICE
(1) Failure of control bus latch ROM U1
BUT “SRQ IN STATUS BYTE” IS
or I/O register selector on PCA A2.
NOT SET”
(2) Failure of microprocessor.
“INTERFACE DOES NOT REQUEST
Same as items (1) and (2) above.
SERVICE.
CANNOT CLEAR “SRQ””
“INTERFACE INCORRECTLY
Same as items (1) and (2) above.
RESPONDED TO SERIAL
CANNOT CLEAR “SRQ””
“IUT WAS ENABLED TO
ON SERVICE REQUEST,
INTERRUPT OCCURRED”
POLL.
INTERRUPT TEST FAILURES
INTERRUPT
( 1 ) F a i l u re o f i n t e r r u p t l o g i c , m i c r o-
BUT NO
processor, or control bus latch on
PCA A2 .
“IUT WAS ENABLED TO INTERRUPT
INTERRUPT ON BECOMING, ACTIVE
CONTROLLER, BUT NO INTERRUPT
OCCURRED”
“IUT WAS ENABLED TO INTERRUPT
INTERRUPT ON BECOMING ACTIVE
TALKER, BUT NO INTERRUPT
OCCURRED”
“IUT WAS ENABLED TO INTERRUPT
INTERRUPT ON BECOMING ACTIVE
LISTENER, BUT NO INTERRUPT
OCCURRED”
(2) Failure of output data latch on PCA
A2.
(1) Same as items (1) and (2) above.
(2) Failure of computer command register
or interrupt logic on PCA A1.
Same as items (1) and (2) above.
F a i l u r e o f i n t e r r u p t l o g i c , m i c r o p r o c e s-
s o r , c o n t r o l b u s l a t c h , o r d a t a i n p ut
multiplexer on PCA A2.
4-249
