Page 2.5
6-CHANNEL BATTERY SIMULATOR MODULE 41-752
pickering
SECTION 2 - TECHNICAL DESCRIPTION
41-752 INTERLOCK SYSTEM
The 41-752 can be used for simulating large numbers of series connected batteries which can potentially generate
high output voltages relative to PXI ground. The user connector has an interlock feature that can be used to inhibit
the generation of output voltage if the user connector is not in place.
The user connector has the following control pins:
●
A 3.3V output from a 100Ω series protection resistor
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A connection to PXI Front Panel Ground
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An Enable pin which is by default pulled low by a 10kΩ resistor. NO OUTPUT VOLTAGE WILL BE
GENERATED BY THE BATTERY SIMULATOR UNLESS THIS PIN VOLTAGE IS RAISED TO 3.3V.
The pin can be raise to 3.3V by connecting to the supplied 3.3V pin above. This is a global Enable for
all 6 channels on the module. If the Enable pin is allowed to be set low then the 41-752 will continue to
disable its battery simulator outputs until the software resets the channels to be on.
●
A Status Readback pin which is raised to 3.3V when the Enable pin is set high AND the software has
reset the 41-752 to enable the battery simulator output. This is available as physical signal on the user
connector and its status can be read back over the PCI interface by the software driver.
In addition the software driver can turn individual battery simulator channels on and off.
The interlock can be used in a variety of ways when multiple modules are used in a system:
●
All the Enable pins can be linked together and a single switch used to pull the Enable high to 3.3V. The
enable pin can be pulled high using a user connection. The software driver can then enable or disable
individual channels.
●
All but one of the Enable pins can be connected together and connected to the Readback Status pin
of one of the modules (Master Module). The Master Module then has its Enable pin connected high
(3.3V). To restart the system the software driver would then have to enable each module through the
Master Module’s Module Enable and then turn on each battery simulator through its Module Enable. To
avoid high dynamic loads on the chassis backplane Pickering Interfaces recommends that each module
is restarted in a sequence that avoids an excessively high rate of PSU load change.
●
Each module can be independently controlled by linking its Enable pin to its 3.3V pin, if the user
connector is disconnected the battery simulator will shut down and will require restarting through its
software driver control. The act of removing the user connection will in any case remove that module
from the serial chain and disrupt the generation of output voltage.
●
The Status Readback output from one module can be connected to the Enable of the next module in
the series chain. Disconnection of the user connector will result in all modules further down the chain
being turned off. As in the previous cases when the user connection is re-established the software drive
will need to restart the system.
It should be emphasized that if the Enable pin of the module is set low, even temporarily, the 41-752 will not
automatically turn back on when the Enable returns high. The software driver must be used to turn the channels
back on.
