User manual

Chapter 1 Series 1700 Introduction
1-1
20 Gear Drive, Plymouth Ind. Park, Terryville, CT 06786
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This chapter serves as an introduction to the Series 1700 modules. It highlights
the Series 1700 family members, potential applications, compatible transducers,
and all of the modules’ features, including those added since the last revision.
Overview
The Series 1700 modules are Allen Bradley 1771
I/O compliant cards that convert resolver signals to
digital position and tachometer data that can be
reported over the backplane using either block or
single transfers. The 1700 modules eliminate the
separate resolver decoder box, PLC input card, and
associated wiring needed to bring the digital data
into a PLC.
Like an absolute optical encoder, a resolver is a
sensor that converts an angle into electrical signals.
However, this is where the similarities end. The
resolver is an analog device that does not contain
sensitive components such as optics and electronics
that may be damaged by severe environmental
conditions. Also, the position resolution of a
resolver is limited only by the electronics that decode
its signals. When attached to a 1700 module, the
resolver gives an absolute position value with up to
thirteen bit position resolution over a six conductor
cable.
A 1700 module application generally falls into one of two categories.
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Rotary Application -
The resolver position directly correlates to an angular position on
the machine. One example is monitoring a press ram. As the press cycles through one
turn, the resolver position is used to monitor and control such functions as material feed
and part blow-off.
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Linear Application -
The resolver position correlates to a physical length. These
applications can be either single turn or multi-turn. An example of a single turn
application is a packaging machine where the resolver completes one turn for each
product. Here the resolver position is used to control when glue is applied or when the
package is cut to length. An example of a multi-turn application is monitoring the
position of a load on either a track or ball screw. In this type of application, linear
position is translated to rotary position through either a wheel or gearing. The
transducer completes several rotations in order to travel the complete distance.
AMCI also has a line of cable reel transducers for use in linear applications. A cable
reel transducer has a stranded stainless steel cable wrapped around a spring loaded
drum. As the cable is pulled out of the transducer, the drum rotates, which in turn
rotates the internal resolver. The cable is retracted by the force of the drums' spring.
Distances of up to forty-five feet can be measured with these transducers.
Physically, the Series 1700 modules are two slot cards that have one, two, three, or four
resolver inputs, called resolver, or transducer, channels. Their integral keyboard and display
allow you to setup the module and monitor position and tachometer data.
Figure 1.1 1700 Module & HT-20