User manual

G-2 GPIB 488.1 Protocol 2400 Series SourceMeter
®
User’s Manual
Introduction
The SourceMeter supports two GPIB protocols: SCPI and 488.1. The 488.1 proto-
col is included to significantly increase speed over the GPIB.
When using the 488.1 protocol, throughput is enhanced up to 10 times for data
sent to the SourceMeter (command messages) and up to 20 times for data
returned by the Source-Meter (response messages). The speed of readings sent
over the GPIB is also increased; see “Multiple TALKs on the same query are sup-
ported as in the SCPI protocol. This feature is useful when reading back long
ASCII strings.,” page G-5, for details.
NOTE With the 488.1 protocol selected, you will still use SCPI commands to
program the SourceMeter. Operation differences between the two proto
-
cols are discussed in this appendix.
Selecting the 488.1 protocol
Perform the following steps to select the 488.1 protocol:
1. Press MENU to display the MAIN MENU.
2. Place the cursor on COMMUNICATION and press ENTER to display the
COMMUNICATIONS SETUP menu.
3. Place the cursor on GPIB and press ENTER to display the present GPIB
address.
4. Press ENTER to display the GPIB PROTOCOL menu.
5. Place the cursor on 488.1 and press ENTER.
6. Use the EXIT key to back out of the menu structure.
When switching between the SCPI protocol and 488.1 protocol, the instrument
does not reset. The GPIB protocol setting is saved in EEPROM, and the unit will
power up with that selected protocol.
The GPIB protocol cannot be changed over the bus. However, there is a query
command to determine the presently selected protocol. When the 488.1 protocol
is selected, the message exchange protocol (MEP) disables. Therefore, if you use
the following query to request the state of MEP, you will know which protocol is
enabled:
:SYSTem:MEP[:STATe]?
If a “1” is returned, MEP is enabled, and the SCPI protocol is selected. A “0” indi-
cates that MEP is disabled, and the 488.1 protocol is enabled. To summarize:
1 = SCPI protocol