On Wed, 6 Aug 1997 21:43:00 -0700, Phil ESGUERRA asked:
|Does anyone remember the maximum allowed distance of an HP-IB device
|from the HP3000?
|
|I am trying to relocate an HP2680 (Laser printer), and I am having
|difficulty printing to it. I suspect that it could be the length of the
|HP-IB cable to the printer.

The maximum allowed length for *all cable* (including internal cabling)
on an HP-IB bus is 15m, regardless of the number of devices.  However,
it may be as short as 8m.  The actual rule is called the "7+1 rule" and
works like this: Each HP-IB device has an attribute called a "device load".
Most devices default to one device load, but some devices allow the device
load to be configured to other values.  The total device load for all
devices on the bus must be between 1 and 8 device loads (inclusive).
The maximum allowed cable length for all devices on the HP-IB bus is seven
meters plus one additional meter for each device load.

In your example, with only the single 2680 on the bus, if the device load
is one then the max cable length is eight meters.  If the device load can
be configured for eight, then the maximum length is 16 meters.  I vaguely
recall that the 2680 may have the device load configured at one, two or four
loads, but I'm not at all certain those numbers are accurate or the only
options.
--
Jeff Woods
[log in to unmask] at Unison Software
[log in to unmask]   at home  [PGP key available here via finger]

"I speak Spanish to God, Italian to women, French to men, and
 German to my horse."  --  Charles V (1500-1558), Holy Roman Emperor