Using the GP-IB Interface
9-5
IM 755601-01E
9
9.3 Responses to Interface Messages
Multi-line messages
Eight data lines are used to transmit multi-line messages. The messages are classified
as follows:
Address commands
These commands are valid when the instrument is designated as a listener or 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)
PPC (Parallel Poll Configure)
SDC (Selected Device Clear)
GET (Group Execute Trigger)
Commands that are valid on an instrument that is designated as a talker
TCT(Take Control)
Universal commands
These commands are valid on all instruments regardless of the listener and talker
designations. The following five commands are available.
LLO (Local Lockout)
DCL (Device Clear)
PPU (Parallel Poll Unconfigure)
SPE (Serial Poll Enable)
SPD (Serial Poll Disable)
In addition, listener address, talker address, and secondary commands are also
considered interface messages.
Interface Messages
Uni-line
Messages
Address
command
Universal
command
♦
IFC
♦
REN
IDY
♦
GTL
♦
SDC
PPC
♦
GET
TCT
♦
LLO
♦
DCL
PPU
♦
SPE
♦
SPD
Listener
address
Talker
address
Secondary
command
Multi-line Messages
The instrument supports those interface messages that are indicated with “
♦
” marks.
Note
The differences between SDC and DCL
Of the multi-line messages, SDC messages are those that require talker or listener
designation and DCL messages are those that do not require the designation. Therefore,
SDC messages are directed at a particular instrument while DCL messages are directed at all
instruments on the bus.