Seaward DO5000 Interface - Manual (Page 7)

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TE0 Extended Talker Capability
Extended talker addressing is not implemented.
L3 Listener
Capability
The device; can act as a basic listener
; can be set to listen only mode
; becomes unaddressed if MTA sent
LE0
Extended Listener Capability
Extended listener addressing is not implemented
SR1 Service Request Function
The device can asynchronously assert the SRQ line to request the attention of
the system controller.
RL1 Remote/Local
Function
The device has full remote/local switching capability. There is no manual
switch on the instrument.
PP0
Parallel Poll Function
The parallel poll function is not implemented.
DC1 Device Clear Function
The device may be set to the default state by the appropriate command, and
includes a selective device clear.
DT1
Device Trigger Function
The device may be triggered by the appropriate commands.
C0 Controller
Function
The controller function is not implemented, and hence the instrument cannot
behave as a system controller. Talk Only mode is available for minimal bus
use.
E2 Driver
Electronics
All lines are tri-state outputs except SRQ, NRFD and NDAC which are open-
collector.
3.4 Single Wire Interface Messages
The IEEE bus consists of 8 data lines, 5 General Interface Management Lines and 3
Handshake lines.
The 3 Handshake lines are;
DAV Data
Valid
Asserted by the talker to indicate that data has been put onto the data bus.
NRFD Not Ready For Data
Asserted by the listener to indicate that it is busy and is not ready to receive
data.
NDAC Not Data Accepted
Negated by the listener to confirm receipt of a data byte.