User manual

IEEE-488 Reference
4-36 2001-900-01 Rev. J / October 2009
:STATus:QUEue?
:SYSTem:ERRor?
After sending either of the above commands, the oldest message in the Error Queue will be
moved to the Output Queue. When the Model 2001 is then addressed to talk (as explained
above), the response message will be sent to the computer.
2. Multiple response messages: If you send more than one query command in the same program
message (see Multiple command messages), the multiple response message for all the queries
will be sent to the computer when the Model 2001 is addressed to talk. The responses are sent
in the order that the query commands were sent and will be separated by semicolons (;). Items
within the same query are separated by commas (,). The following example shows the response
message for a program message that contains four single item query commands:
0; 1; 1; 0
3. Response Message Terminator (RMT): Each response message is terminated with an LF (line
feed) and EOI (end or identify). The following example shows how a multiple response message
is terminated:
0; 1; 1; 0 <RMT>
4.9.4 Message exchange protocol
The message exchange protocol can be summarized by the two following rules:
Rule 1. You must always tell the Model 2001 what to send to the computer.
The following two steps must always be performed, in this order, to send information from the
instrument to the computer:
1. Send the appropriate query command(s) in a program message.
2. Address the Model 2001 to talk.
Rule 2. The complete response message must be received by the computer before another
program message can be sent to the Model 2001.