Fluke 2625A User Manual

Page of 310
IEEE-488 Option -05
List of Replaceable Parts
7
7-9
7-18.  Failure to Receive Multiple Character Commands
Monitor the IRQ2* interrupt signal from A5U1-10 during attempts to communicate with
the instrument. Each byte received with the ATN signal (A5U1-31) high should cause
the interrupt signal to go low. Verify that the signal arrives at A5J1 properly. An
interrupt not detected by A1U4 will remain low indefinitely. A5U1-10 will go high only
when both the interrupt is detected and the received byte is removed from A5U1 by
A1U4.
7-19.  Failure to Transmit Query Responses
Check that TE (A5U1-23) goes high when the interface is addressed to talk. This signal
must go high to allow the bus interface transceivers to change the direction of DIO1
through DIO8, EOI, DAV, NRFD, and NDAC. Verify that each of these signals passes
through A5U2 and A5U3 properly.
7-20.  Failure to Generate an End or Identify (EOI)
When the IEEE-488 option sends the Line Feed termination character at the end of a
response, the EOI signal should also be set true. When EOI is true, A5U1-30 should go
low. Follow this signal from A5J2 through A5U3 to A5U1.
7-21.  Failure to Generate a Service Request (SRQ)
When a Service Request is being generated, A5U1-32 should be low. Follow this signal
through A5U3 to connector A5J2. When a Serial Poll (SPL) is performed by the IEEE-
488 bus controller, A5U1-32 will go high again.
Note
If the instrument is in the remote state without front panel lockout (i.e.,
REMS), a service request can be sent from the front panel by pressing the
up arrow button.
7-22. List of Replaceable Parts
Refer to Section 6 for an illustrated parts list of the IEEE-488 Option.
7-23. Schematic Diagram
The schematic diagram for the IEEE-488 Option is included in Section 8 of this manual.