CDR-3250/80 TECHNICAL MANUAL
Issue 2.2
3-69
Table 3-6 IEEE-488 Bus Management Signals.
Name (Mnemonic)
Description
Attention (ATN)
Causes all devices to interpret data on the bus as a controller command. When ATN is
true, the bus is placed in the "Command Mode". All devices on the bus interpret data on
the eight data lines as commands. When ATN is false, the bus is placed in the "Data
Mode". All active listeners on the bus interpret data on the eight data lines as data.
Interface Clear (IFC)
Clears the bus. Sets the bus to an idle state.
Service Request (SRQ)
Alerts the controller to a need for communication.
Remote Enable (REN)
Enables devices to respond to remote program control when addressed by the controller.
End or Identify (EOI)
Indicates last byte of multibyte sequence.
Table 3-7 IEEE-488 Bus Handshake Lines.
Name (Mnemonic)
Description
Data Valid (DAV)
Sent by source to indicate that data on the bus is valid. All active devices on the
bus can accept the byte as true information.
Not Ready for Data (NRFD)
Sent by acceptor to indicate that a device is not ready to accept data.
Not Data Accepted (NDAC)
Sent by acceptor to indicate that the data byte has not yet been read from the bus.
Table 3-8 IEEE-488 Implemented Interface Capabilities.
Mnemonic
Description
SH1
Source Handshake, complete capability
AH1
Acceptor Handshake, complete capability
T6
Basic Talker, with serial poll and unaddress if MLA, no Talk Only mode
TE0
No Extended Talker
L4
Basic Listener, unaddress if MTA, no Listen Only mode
LE0
No Extended Listener
SR1
Service Request, complete capability
RL2
Remote Local, no local lockout
PP0
Parallel Poll, no capability
DC1
Device Clear, complete capability
DT0
Device Trigger, no capability
C0
Controller, no capability
E2
Three state line drivers
Courtesy of http://BlackRadios.terryo.org
