7-9
IM 2553A-01EN
GP-IB Interface
3
2
1
4
5
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7
8
9
10
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14
App
Index
Multi-line Messages
Eight data lines are used to transmit multi-line messages. The messages are classified as follows:
• Address Commands
Some address commands are valid when a device is designated as a listener, and some are
valid when it is designated as a talker. The following five commands are available.
Commands that are valid on an instrument that is designated as a listener
• GTL(Go To Local)
• SDC(Selected Device Clear)
• PPC(Parallel Poll Configure)
• GET(Group Execute Trigger)
A command that is valid on an instrument that is designated as a talker
• TCT(Take Control)
• Universal Commands
Universal commands are available to all devices regardless of their listener or talker designation.
The following five commands are available.
• LLO(Local Lockout)
• DCL(Device Clear)
• PPU(Parallel Poll Unconfigure)
• SPE(Serial Poll Enable)
• SPD(Serial Poll Disable)
There are other interface messages: listener-address, talk-address, and secondary commands.
Interface messages
Uni-line
messages
Address
commands
Universal
commands
Listener
address
Talker
address
Secondary
command
Multi-line messages
The 2553A supports interface messages marked with a
«
.
Note
Difference between SDC and DCL
In multi-line messages, SDC messages are those that require talker or listener designation and DCL
messages are those that do not require a designation. Therefore, SDC messages are directed at a particular
instrument while DCL messages are directed at all instruments on the bus.
7.4 Responses to Interface Messages
