Measurement Computing WaveBook rev.3.0 - Manual (Page 38)

3-6 WBK14, WBK Expansion Options WaveBook User’s Manual
WBK11 - Simultaneous Sample & Hold Card
Description
WBK11 is a simultaneous sample-and-hold card (SSH) that can be installed in the field. The card can
simultaneously sample 8 channels. WBK11 can be installed inside a WaveBook or a WBK10/10H and is
controlled by the WaveBook. WBK11 allows concurrent (<150 ns) capture of multiple input channels and
virtually eliminates channel-to-channel time skewing.
When using WaveBook with an SSH channel enabled, the per-channel sample rates are
reduced. The rate reduction is the same as that which would occur if another channel
were added. The per-channel rate (with SSH enabled) is:
1 MHz / (n+1), where n is the number of active channels.
The WBK11 SSH card can accommodate higher gains than the main unit because its gains are fixed for
each channel prior to the acquisition. Each channel may be set, in software for ranges shown in the table.
All channels equipped with SSH circuitry are sampled simultaneously as a system.
The figure shows a block diagram of the WBK11. All connections are through P10 and P11.
Offset Adjust
Diff. Amp.
Sample/
Hold
+
PGA
-
One of 8 Channels (Typical)
MUX
Buffer
Amplifier
P10
mates
with
WaveBook
J10
P11
mates
with
WaveBook
J11
SCI - Serial
Configuration Interface
Octal
DAC
WBK11 Block Diagram
Hardware Setup
Configuration
All WBK11 configurations are controlled by software. There are no hardware settings.
Installation
The WBK11 connects to headers J10 and J11 in the base unit. The base unit can be a WaveBook/512,
/512H, WaveBook/516, or WBK10/10H. The jumpers located on J10 and J11 provide signal pass-through
when the WBK11 is not installed. Use the following steps to install the WBK11 into a WaveBook, or
WBK10/10H module.
Although the next figure represents installation of a WBK11 into a WaveBook/512,
installation into other WaveBooks (and WBK10/10H) are similar. Note that the
following steps should be used when installing WBK11, WBK12, or WBK13.
1. Remove all power from the unit and any connected devices.
2. For WaveBook/512 series only, remove the screw holding down the top panel (cover), and slide the
panel out towards the back.
For WaveBook/516 only, remove four side screws and lift the cover free of the chassis.
3. Remove present board from J10 and J11. If no board is installed in J10 and J11, skip to step 4.
If a board is already installed:
(a) remove that board’s stand-off screws
(b) remove the board
Note: Unless a special order has been placed, WaveBook/516 series is shipped with a PGA card
installed.