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
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