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2-8
IM AQ6370C-17EN
Multiline Messages
A message is sent through eight data lines. Multiline messages come in the following
categories.
Address Commands
These commands are valid when the device is specified as the listener or the talker.
The following are the five types of address commands.
Commands valid for devices specified as listeners
GTL (Go To Local)
SDC (Selected Device Clear)
PPC (Parallel Poll Configure)
GET (Group Execute Trigger)
Commands valid for devices specified as talkers
TCT (Take Control)
Universal Commands
These commands are valid for all devices regardless of whether they are specified as
listeners, talkers, or neither. The following are the three types of universal commands.
LLO (Local Lockout)
DCL (Device Clear)
PPU (Parallel Poll Unconfigure)
Additionally, an interface message can consist of a listener address, talker address, or
secondary command.
Interface Messages
Uniline
messages
Address
commands
Universal
commands
IFC
REN
IDY
GTL
SDC
PPC
GET
TCT
LLO
DCL
PPU
SPE
SPD
Listener
address
Talker
address
Secondary
command
Multiline messages
A star indicates an interface message supported by this instrument.
Note
Differences between SDC and DCL
Of the multiline messages, SDC is an address command requires specification of the talker
or listener, and DCL is a universal command that does not require specification of the talker
or listener. Therefore, SDC is applicable only to certain devices, but DCL is applicable to all
devices on the bus.
2.5 Responses to Interface Messages