Chapter 7 Input/Output Modules; Basic I/O Module Types - GE 90-30 PLC Series Installation And Hardware Manual

Input/Output Modules
Chapter
7
The basics of the Series 90-30 Input and Output (I/O) modules are covered in this chapter for your
convenience. A table listing these modules is located at the end of this chapter. For detailed
specifications and installation instructions, please refer to publication GFK-0898, Series 90-30 PLC
I/O Module Specifications.

Basic I/O Module Types

GFK-0356Q
Discrete Input
Series 90-30 discrete input modules convert AC and DC power levels from user devices to the
logic levels required by the PLC. An optical coupler provides isolation between the incoming
power and the logic circuitry. Discrete input modules with 8, 6, or 32 points are available.
Discrete Output
Series 90-30 discrete output modules convert logic levels into AC or DC power levels required
for driving user supplied devices. Either a power semiconductor or an electromagnetic relay
switches each output point. The discrete output semiconductor-switched modules are available
with 5, 8, 2, 6, or 32 output points. Relay output modules are available with either 8 or 6
Normally Open relay contact outputs.
Discrete Input/Output
Combination discrete input/output modules combine AC inputs and relay outputs or DC
inputs and relay outputs on one module. Each of these modules have 8 input circuits and 8
relay output circuits on one board.
Analog Input
Series 90-30 analog input modules provide A/D (Analog to Digital) conversion by converting
an analog input signal into a scaled digital number which will be transferred into the PLC's
%AI memory. Analog input modules are provided in four versions, ( ) a 4-channel current
module, (2) a 4-channel voltage module, (3) a 6-channel high-density current input module,
and (4) a 6-channel high-density voltage input module.
Analog Output
Series 90-30 analog output modules provide D/A (Digital to Analog) conversion by converting
a scaled digital number (from the PLC's %AQ memory) into an analog output voltage. Analog
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