HP-IB
Jump to navigation
Jump to search
- Hewlett-Packard Interface Bus
- IEEE-488
- IEEE Standard 488-1975
- Up to 15 devices per interface, each set to an address 0–30 (#21 reserved for desktop computer; #31 indicates device is in ‘listen-only’ mode)
Controller types
- Active Controller
- Current controlling device on bus
- System Controller
- Can take priority control even if it is not currently the active controller
Signaling
- Multipoint bus
- 16 signal lines
Data Lines
- DIO1 to DIO8
- 8 line data bus; byte-serial/bit-parallel
Data Byte Transfer Control (handshake lines)
- DAV
- DAta Valid
- NRFD
- Not Ready For Data
- NDAC
- Not Data ACcepted
General Interface Management
- IFC
- InterFace Clear
- ATN
- ATtentioN
- Data lines used for commands or 7-bit addresses when ATN activated
- SRQ
- Service ReQuest
- A device has something it wishes to share
- REN
- Remote ENable
- Sets devices for either remote or local control
- EOI
- End Or Identify
- Indicates end of a multi-byte sequence, or device status if used with a data line and ATN
Device types [1]
- Talkers
Devices which send information on the bus when they have been addressed.
- Listeners
Devices which receive information sent on the bus when they have been addressed.
- Controllers
Devices that can specify the talker and listeners for an information transfer.
Message types
- Note: not all devices support all message types
- Data
- Trigger
- Clear
- Remote
- Local
- Local Lockout
- Clear Lockout and Set Local
- Also clears ‘Remote’
- Require Service
- Status Byte
- Status Bit
- Simultaneous status of a group of devices
- Pass Control
- Abort
References
- ↑
- Chapter 3 of http://www.hpmuseum.net/document.php?hwfile=2872