Specifications

AVG Automation would like to introduce you to a unique
position encoder, the Programmable Position Transducer or
PPT. The PPT is an absolute position sensing device which
accepts resolver inputs, converts position data to 5-digit BCD
output, and is prescalable and presettable over a wide-range of
electronic gear ratios. It operates in a single-or multi-turn
mode with high-accuracy and can resolve linear distances of 1
part in 100,000 whether it be 0.001" (0.025 mm) over 100"
(2540 mm) or 1 foot (304.8 mm) over 18.93 miles (30.46
km) of travel. The versatile electronic design assures simple
interface to other limit setting or control devices.
The PPT consists of two parts, one is a position sensor
mounted on the machine shaft and the other is a programma-
ble unit mounted in the machine control panel. The position
data from the sensor is converted to binary data by an internal
ratiometric converter in the programmable unit, processed in
the microprocessor together with other program variables and
displayed on the front panel display. A parallel BCD output is
also made available to provide information to other systems
requiring positional data.
Prescalable, Presettable; Yet Absolute
A wide-range of easy to set programmable scale factors elimi-
nates the need of mechanical gear trains and prescales the dis-
play to readout directly in engineering units. Any preset num-
ber can be jammed into the position "counter" by a front
panel switch or an external signal, thus "offsetting" or "rezero-
ing" the machine in no time.
The PPT is unique in that it can be prescaled and preset and
still is absolute over the entire-range in single-turn operation.
In multi-turn applications it keeps track of the true position, if
the resolver movement does not exceed half-a-revolution
(<180°) after power loss.
Simple Front-Panel Programming
The PPT is fully front-panel programmable for all variables,
and yet secure against any unauthorized program changes.
Opening of an external user-provided keyswitch inhibits any
program changes on the front panel.
THE M1890-R
M1890 PROGRAMMABLE POSITION
TRANSDUCER AND PROGRAMMABLE
SELSYN INDICATOR
◆ M1890-R Programmable absolute position sensor,
resolver input, 5-digit BCD output
◆ M1890-S Solid-state replacement for
electromechanical Selsyn systems
◆ Prescalable, presettable; yet absolute
◆ Simple front panel programming of counts-per-
turn, no mechanical gear trains
◆ No batteries, nonvolatile EEROM memory
◆ PC handshake for PLC synchronization
◆ Reliable under extreme environments, splash-proof
oil-tight front plate
◆ 1 Part in 100,000 resolution and repeatability
◆ Add limit settings externally
◆ Optional serial link to computers or remote
displays
800-TEC-ENGR
www.avg.net
A-38
Position Transducers/Sensors