User Manual

2400 Series SourceMeter
®
User’s Manual GPIB 488.1 Protocol G-3
0 = 488.1 protocol
Protocol differences
The following information covers the differences between the 488.1 protocol and
the SCPI protocol.
Message exchange protocol (MEP)
When the 488.1 protocol is selected, the MEP is disabled to speed up GPIB oper-
ation.
The following guidelines/limitations must be followed when using the 488.1 proto-
col:
• If a query is sent, it must be the only command on the line (this limitation
also means no multiple queries can be sent). Otherwise, full SCPI com
-
mand syntax is still supported including long-form and short form com-
mands, multiple commands, and MIN/MAX/DEF parameter definitions.
For example, the following command strings are invalid:
:VOLT:RANG 10;*OPC?
:RES:RANG?;:READ?
:READ?;:READ?
The following command strings are valid:
:SOUR1:VOLTage:STARt 1;STOP 10;step 1
:volt:nplc 1.0;:curr:rang min
:RES:RANG? MAX
:READ?
• When a query is sent, either the data must be read back or a Device Clear
(DCL) or Interface Clear (IFC) must be performed to reset the query.
• When sending a command or query, do not attempt to read data from the
SourceMeter until the terminator has been sent (usually Line Feed with
EOI).
Otherwise, a DCL or IFC must be sent to reset the input parser.
• When receiving data, all data, up to and including the terminator (LF with
EOI), must be accepted. Otherwise, a DCL or IFC must be sent to reset the
output task.
• Empty command strings (terminator only) should not be sent.