Keithley 194 Instruction Manual page 270

APPENDIX G
BUS COMMANDS
Commands associated with the IEEE-488 bus can bc
grouped into the following three general categories. Rcfcr
to 'Table G-l.
Uniline Commands-l'hese commands are asscrtcd bv wt~
ting the associated bus line true. For example, to ,issert
REN (Remote Enable), the REN line would bc set lo\\
(true).
Multiline Commands-Gcncral bus commands which arc'
sent over the data lines with the ATN lint true.
Device-dependent Commands-C'i)mm~~~~~~s whose me,m
ings depend on the device in question. 'f'hes~! ctunm.lnds
are transmitted via the data lines while ATN is false.
Figure G-2. IEEE Handshake Sequence
Table G-l. IEEE-488 Bus Command Summary
Command Type
Uniline
Multiline
Universal
Addressed
Unaddressed
Device-dependenl
Command Command
REN (Remote Enable) REN (Remote Enable)
EOI EOI
IFC (Interface Clear) IFC (Interface Clear)
ATN (Attention) ATN (Attention)
SRQ SRQ
LLO (Local Lockout)
DCL (Device Clear)
SPE (Serial Enable)
SI'D Serial Poll Disable)
SDC (selective Device Clear)
GTL (Go To Local)
GET (Group Execute Trigger)
UNL (Unlisten)
UNT (Untalk)
Defines data bus contents.
Controlled bv external device.
Lrxks out local operation
Returns device to default alnditions.
Enables serial polling.
Disables serial polling.
Returns unit to default conditions.
Returns device to local.
Triggers device for reading.
Removes all listeners from bus.
Removesanytalkers from bus.
l'rograms Model ~194 for various mudcs.
*Don't Care
G-3