Baseplate Terms - GE 90-30 PLC Series Installation And Hardware Manual

Baseplate Terms

Backplane: Refers to the circuit board in the baseplate. It contains the baseplate circuitry and
sockets for plug-in modules.
Rack: This term applies to an assembly consisting of a baseplate, power supply, and other
modules.
Rack Number: In systems that require more than one rack, each rack is given its own unique
number, which enables the CPU to distinguish one rack from another. The CPU rack always has a
rack number of 0 (zero).
Slot Number: Each module location (called a "slot") on a baseplate has a unique number (except
for the unnumbered left slot, which is for the Power Supply). The slot to the right of the Power
Supply slot is always called Slot 1. These slot numbers are marked on the baseplate's plastic
cover. Each slot has a connector for module connections and top and bottom retainers for holding
the module in place.
Module Location: Since each rack is assigned a unique number, and since each slot in a rack's
baseplate has a unique slot number, each individual module's location in a system can be identified
by its rack and slot numbers. For example, a module could be referred to as "the module in Rack 1,
Slot 4." This numbering method enables the CPU to correctly read from and write to a particular
module, and report the location of a faulted module.
CPU Baseplate: A baseplate that either has a CPU built-in to its backplane circuit board
(embedded CPU) or one that has a slot for a plug-in CPU module (modular CPU). There can only
be one CPU baseplate in a Series 90-30 PLC system and it will always be called Rack 0 (zero). A
CPU module can only mount in Slot 1 of a modular CPU baseplate. A few special Option
modules, such as the FIP Remote I/O Scanner module (IC693BEM330) can also be used in Slot 1
of a modular CPU baseplate. Power Supply, Input/Output (I/O), and most Option modules cannot
fit in a CPU slot.
Expansion Baseplate: One that does not contain a CPU and that can be mounted up to 50 cable-
feet from the CPU baseplate. An Expansion baseplate cannot operate on its own. It must be used
in a system that has a controlling CPU.
Remote Baseplate: One that does not contain a CPU and that can be mounted up to 700 cable-feet
from the CPU baseplate. A remote baseplate cannot operate on its own. It must be used in a
system that has a controlling CPU.
Power Supply Slot: Each baseplate must contain its own Power Supply module, which must
mount in the Power Supply slot. It is the slot located on the left end of the baseplate, it is not
numbered, and it has a unique size and shape so that only a Power Supply module can mount in it.
GFK-0356Q Chapter 3 Baseplates
Attempts to force a module into an improper slot type will damage the
module and/or the baseplate. Modules will mount in the correct slot easily
and with a minimum of force.
Caution
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