PCB Piezotronics 443B02 Installation And Operating Manual page 12

Chassis: Models
441A42, 441A43, 441A45 and 441A49
The PCB Series 440 Modular Chassis is the enclosure into
which the modules of the PCB Modular Signal
Conditioning System are inserted. Its configuration varies
by model, ranging from two slots to nine; one slot is
reserved for the power supply, while Eurocard-style plug-
in modules occupy the remaining slots and are secured
to the inside frame using mechanical fasteners. A circuit
board assembly in the rear of the chassis distributes
power to the modules and provides the means by which
modules communicate with each other, the rest of the
system, and a personal computer.
Models 441A33, 441A35 and 441A38 are the computer-
controlled, master versions of the standard chassis. The
back panel of these master chassis have two RS-485
connectors marked IN and OUT and one RS-232 connector.
Models 441A45 and 441A49 are slave chassis designed to
be controlled by the masters. Slave chassis also have two
RS-485 connectors, but no RS-232 connector. In a multiple
chassis system, the master controller communicates to the
other modules via the common RS-485 network and to the
computer via the RS-232 connection.
Equipment Ratings
This equipment operates at 104F (40C), in an
environment having 93% relative humidity. Its frequency
range is 50/60 Hz. Operation of this unit is limited to
environments having an altitude of less than 2 000 meters.
The pollution degree for operation of the Model 440 is two
(2), meaning that normally, only non-conductive pollution
occurs. The over voltage category is II, indicating the
transient voltage levels that may be tolerated by the
equipment.
Multiple Chassis Configuration
High voltage electrostatic discharge
(ESD) can damage electrical devices.
To avoid triboelectric transfer:
1. Connect the cables only with the AC power off.
2. Temporarily "short" the end of the cable before
attaching it to any signal input or output.
Each master controller can control up to four chassis filled
with modules. Each chassis (or rack) must, however, be
uniquely defined. This is accomplished by setting rack
addresses. There are two jumpers on the upper right
Manual 19680 Rev. C
ECN 50523
441A33, 441A35,
CHASSIS AND POWER SUPPLY
portion of the backplane labeled RAD1 and RAD0, as shown
on Figure 1 in Appendix A. The settings are as follows:
RAD1
Rack 1 Low
Rack 2 Low
Rack 3 High
Rack 4 High
Refer to Figure 2 in Appendix A for a four-rack
configuration. Notice on the drawing that the RS-485 IN
connection on Rack 1 requires termination, as does the 485
OUT connection on Rack 4. The 485 IN is terminated with
the TER1, TER2 and TER3 terminators on the backplane.
The termination settings are also shown.
Changing the Fuse
Two rear panel fuses, located below switch in the AC
receptacle, protect the power line inputs of the instrument.
The fuse type is a T 1.6A, L 250 V. To change the fuse,
disconnect the power cord. Find the slot just above the
power switch and pull forward to open the door that
exposes the fuse drawers. Pull the individual drawer
forward and insert a new fuse.
Disabling Cooling Fan
If it is necessary to turn off the cooling fan in order to
reduce acoustical noise, a jumper "J2," located on the
motherboard, must be removed. In order to access this
jumper, the rear panel must be taken off. The fan may then
be disabled via a command from the host computer
controlling the master. The fan should be disabled for as
short a period as possible to ensure continuous cooling.
Contact the factory for more details.
Available Modules
For more information on individual modules, please see the
individual manual accompanying each of the following:
2
RAD0
Low
High
Low
High