ChartScan User’s Manual, 11-97 E-1

Appendix E

Bus States, Bus Lines, and Data Transfer Aspects

Bus State Bus Line Data Transfer (DIO) Lines
87654321
Bus Management Lines
IFC Interface Clear
REN Remote Enable
IEEE 488 Interface: Bus Management Lines
ATN Attention (&H04) 00000100
EOI End-Or-Identify (&H80) 10000000
SRQ Service Request (&H40) 01000000
IEEE 488 Interface: Handshake Lines
DAV Data Valid (&H08) 00001000
NDAC Not Data Accepted (&H10) 00010000
NRFD Not Ready For Data (&H20) 00100000
Serial Interface: Bus Management Lines
DTR Data Terminal Ready (&H02) 00000010
RI Ring Indicator (&H10) 00010000
RTS Request To Send (&H01) 00000001
Serial Interface: Handshake Lines
CTS Clear To Send (&H04) 00000100
DCD Data Carrier Detect (&H08) 00001000
DSR Data Set Ready (&H20) 00100000
Hexadecimal & Decimal Values
Hex Value (QuickBASIC) &H80 &H40 &H20 &H10 &H08 &H04 &H02 &H01
Decimal Value 128 64 32 16 8421
Bus State IEEE 488 Bus Command Data Transfer (DIO) Lines
(ATN is asserted “1”) 87654321
DCL Device Clear 00010100
GET Group Execute Trigger (&H08) 00001000
GTL Go To Local (&H01) 00000001
LAG Listen Address Group (&H20-3F) 001addrn
LLO Local Lock Out (&H11) 00010001
MLA My Listen Address 001addrn
MTA My Talk Address 010addrn
PPC Parallel Poll Config 0110SP2P1P0
PPD Parallel Poll Disable (&H07) 00000111
PPU Parallel Poll Unconfig (&H15) 00010101
SCG Second. Cmd. Group (&H60-7F) 011commd
SDC Selected Device Clear (&H04) 00000100
SPD Serial Poll Disable (&H19) 00011001
SPE Serial Poll Enable (&H18) 00011000
TAG Talker Address Group (&H40-5F) 01 0addrn
TCT Take Control (&H09) 00001001
UNL Unlisten (&H3F) 00111111
UNT Untalk (&H5F) 01011111
Hexadecimal & Decimal Values
Hex Value (QuickBASIC) &H80 &H40 &H20 &H10 &H08 &H04 &H02 &H01
Decimal Value 128 64 32 16 8421