Hp-Hil; General Description; Link Controller - HP 9000 Series 310 Service Information Manual

HP-HIL
General Description
Hewlett-Packard Human Interface Link (HP-HIL) is an HP standard for interfacing Series 300
computers and other workstations to human input devices. A list of all devices is shown in Table
3-2.
Asynchronous serial communications protocol enables you to select a set of input devices, connect
them to your computer, and work with any application program.
HP-HIL circuits exist on the following assenlblies used in Series 300 computers:
• 98561-G6511 Processor Board.
• 98561-G6512 Processor Board.
• 98561-G6513 Processor Board.
• 98561-G6531 Human Interface Card
A link controller exists on these assemblies to control the HP-HIL. Each HP-HIL device has an
circuit to interface information to and from the device. Limitations for the HP-HIL are:
• Up to seven devices can be on the link.
• Maximum distance between devices is 2.4 metres, total link maXImum length is 16.8
metres. This does not include the 15 or 30 metre extensions.
• Series
~100
Maximum link current is 1 A.
Link Controller
A block diagram of a typical link controller is shown in Figure 3-5.
I
Power
I
+12V
Supply
J
---+
GND
HP-HIL Data
so
SI
HP-HIL Data
Computer
Unk
Interface
11 1\
\J V
System
Micro-
Vt
1\
processor
System-Specific
Components
\J
V
Figure 3-5. HP-HIL Link Controller
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Functional Description