User manual

Table Of Contents
3152B User Manual Publication No. 980935 Rev. M
2-2 Installation Astronics Test Systems
Local Bus
Configuration
A 3152B can synchronize (phase lock) with other 3152B modules
installed in the same VXI chassis
. One of the
synchronization
method
s uses the VXI Local Bus lines (LBUS0-LBUS7).
The Local
Bus has advantages of high bandwidth and the capability to
synchronize any quantity of modules in the same chassis.
To use the Local Bus,
the modules
to be synchronized must be
configured as instructed belo
w, and must be operated in
Modern
Mode
(not Legacy Mode).
NOTE
Originally, configuration of Model 3152B for Local Bus operation
was performed at the factory.
added to allow the user to configure the 3152B.
If you need to configure a 3152B module for Local Bus operation,
and it does not
have the side-panel access
Figure 2-2, contact Customer Support
provided in the Warranty Statement at the front of this manual.
When synchronizing (phase locking) a group of modules, they must
be installed in a contiguous group of slots in the VXIbus chassis. The
reference
module (master)
that the others will synchronize to must be
imme
diately to the left of the other modules (slaves) in the group.
To enable use of the Local Bus, you must install Local Bus jumpers
(supplied with 3152B)
into each module. Figure 2-
2 shows the
installation locations for the jumpers, which you will install onto the
internal
printed circuit board through th
e openings in the side panel.
Each jumper slides onto two header pins,
connecting them together.
It
may be helpful to
use needle-nose pliers to install the jumpers.
The
specific
jumpers required for each 3152B depend on its position
within the synchronized
group:
1. The
first module on the left (master) requires jumpers LK15
and LK16. Do not install LK13 or LK14 on this module.
2. The last module
on the right requires jumpers LK13 and LK14.
Do not install LK15 or LK16.
3. If there are modules between the first and l
ast modules, they
each require jumpers LK13, LK14, LK15, and LK16.
As mentioned above, the 3152B must be in Modern Mode (not Legacy
Mode) to use the Local Bus for synchronizing modules. To place the
3152B in Modern Mode, send the following SCPI command:
FORMat:INSTrument MODern
You may abbreviate the command by omitting all lower
-
case
characters.
When power is cycled, the 3152B defaults to Legacy
Mode, even if it was in Modern Mode while power was being turned
off.
Commands used for controlling local bus synchronization are detailed