Keithley TEC SourceMeter 2510, User Manual

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Models 2510 and 2510-AT User’s Manual Status and Error Messages B-9
• Incorrectly configured IEEE-488 driver. The driver must be configured so that
when talking on the bus it sends line-feed with EOI as the terminator, and when lis-
tening on the bus it expects line-feed with EOI as the terminator. See the reference
manual for your particular IEEE-488 interface.
• Errors when transferring binary data. Many programs such as Test Point, Lab
View, or Visual Basic default to terminating communications with a carriage return
(CR) and/or line feed (LF). When transmitting binary data, a random bit pattern
could be misinterpreted as a CR or LF and terminate communication before all
bytes are transmitted, resulting in this error. To avoid this problem with binary
transfers, change the default terminator to none to avoid problems, and terminate
on EOI only. See the :FORM:DATA command in
“FORMat subsystem,”
page 10-19 , for information on selecting the binary transfer data format.
-420, “Query UNTERMINATED”
This error occurs when you address the instrument to talk, and there is no response mes-
sage to send. The most likely causes are:
• Not sending a query. You must send a valid query to the instrument before address-
ing it to talk.
• Sending an invalid query. If you have sent a query and still get this error, make sure
that the instrument is processing the query without error. For example, sending an
ill-formed query that generates an error -113, “Undefined header” and then
addressing the instrument to talk will generate an error -420. “Query UNTERMI-
NATED” as well.
• Valid query following an invalid command. This situation can occur when you send
multiple commands or queries (program message units) within one command
string (program message). When the Model 2510 detects an error in a program
message unit, it discards all further program message units until the end of the
string; for example:
:SENS:VOLT?; :SOUR:FUNC?
In the above program message, the program message unit :SENS:VOLT? will gen-
erate error -113, “Undefined header,” and the Model 2510 will discard the second
program message unit :SOUR:FUNC? even though it is a valid query.