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IM 701730-17E
Overview of the GP-IB Interface
1
Multi-Line Message
Eight data lines are used to transmit a message. Multi-line messages are classified as
follows.
Address Commands
Valid when the equipment is designated as a listener or a talker. The following five
address commands are available.
• Commands valid for equipment designated as a listener;
GTL (Go To Local)
SDC (Selected Device Clear)
PPC (Parallel Poll Configure)
GET (Group Execute Trigger)
• Command valid for equipment designated as a talker;
TCT (Take ConTrol)
Universal Commands
Valid for any item of equipment, irrespective of whether the item is designated as a
listener or a talker. The following five universal commands are available.
LLO (Local LockOut)
DCL (Device CLear)
PPU(Parallel Poll Unconfigure)
SPE (Serial Poll Enable)
SPD (Serial Poll Disable)
In addition to the above commands, a listener address, talker address on secondary
command can be sent in an interface message.
Interface Messages
Uni-Line
Messages
Address
Command
Universal
Command
◆
IFC
◆
REN
IDY
◆
GTL
◆
SDC
PPC
GET
TCT
◆
LLO
◆
DCL
PPU
◆
SPE
◆
SPD
Listerner
Address
Talker
Address
Secondary
Command
Multi-Line Messages
Messages marked with a “
◆
” are interface messages supported by the DL1720E/
DL1740E/DL1740EL.
Note
Differences between SDC and DCL
The SDC command is an address command and requires that both the talker and listener be
designated; however DCL is a universal command and does not require that the talker and
listener be designated. Therefore, SDC is used for particular items of equipment, while DCL
can be used for any equipment connected to the communications bus.
1.6 Response to Interface Messages
