Allen-Bradley Compact 1769-IR6, Руководство пользователя

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1 Publication 1769-UM005A-EN-P
Chapter
1
Overview
This chapter describes the six-channel 1769-IR6 RTD/resistance Input
module and explains how the controller reads resistance temperature
detector (RTD) or direct resistance-initiated analog input data from the
module. Included is:
•
a general description of hardware features
•
an overview of module and system operation
•
compatibility
General Description
The 1769-IR6 module supports RTD and direct resistance signal
measurement applications that require up to six channels. The module
digitally converts analog data and then stores the converted data in its
image table.
The module supports connections from any combination of up to six
input devices. Each channel is individually configurable via software for 2-
or 3-wire RTD or direct resistance input devices. Channels are compatible
with 4-wire sensors, but the fourth sense wire is not used. Two
programmable excitation current values (0.5mA and 1.0mA) are provided,
to limit RTD self-heating. When configured for RTD inputs, the module
can convert the RTD readings into linearized digital temperature readings
in °C or °F. When configured for resistance analog inputs, the module can
convert voltages into linearized resistance values in ohms. The module
assumes that the direct resistance input signal is linear prior to input to
the module.
Each channel provides open-circuit (all wires), short-circuit (excitation
and return wires only), and over- and under-range detection and
indication.
IMPORTANT
The module accepts input from RTDs with up to 3 wires.
If your application requires a 4-wire RTD, one of the two
lead compensation wires is not used, and the RTD is
treated like a 3-wire sensor. The third wire provides lead
wire compensation. See Chapter 3,
Installation and
Wiring , for more information.
AB PLCs