M1890-R Programmable Position Transducer
- 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
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 I part in 100,000 whether it be 0.00 1 " (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 programmable 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 eliminates the need of mechanical gear trains and prescales the display to readout directly in engineering units. Any preset number can be jammed into the position "counter" by a front panel switch or an external signal, thus "offsetting" or "rezeroing" 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.
No Batteries, Nonvolatile Memory
Nonvolatile EEROM memory retains information indefinitely after power loss or machine shutdown, eliminating batteries and related hazards.
Replacing Electromechanical Selsyn Systems
In new installations, the M I 890-R together with AVG Automation's brushless resolver series RL100 is a 100% solid-state replacement for electromechanical Selsyn systems. In existing Selsyn installations, the model M1890-S can be used.
PC-Handshake for PLC Synchronization
On an external command, such as data transfer command from a PLC, the digital shaft-angle position can be "frozen" at the input of the PC in order to ensure that the data is not sampled during transition from one angle to the next, and that the PLC always reads a valid data.
Reliable Under Extreme Environments
The PPT combines the ruggedness of a brushless resolver and reliability of a solid-state control. The resolver can be mounted on a machine shaft in any hostile environments such as mechanical shock, vibrations, extreme humidity and temperature changes, oil mists, coolants, solvents, etc., and the programmable unit M1890 can be mounted up to 2500 ft (762 in) away in control panel. The splash-proof, oil-tight front plate of the M1890 unit guarantees perfect operation even in unfavorable conditions like steel mills. The ratiometric converter assures high-tracking speed (1800 RPM) and high-noise immunity. The power-interruption relay with I Form C contact can be used for remote indication, alarm or trip. The operation mode (single- or multi-turn) and resolution (8-, 10-, or 12-bit) can be selected from the front panel "Select Function Switch."
Add Limit Settings Externally
A parallel BCD output for AVG Automation's 18 5 5 bus is provided, which permits setting of limits or trip points externally using 1855 series limit modules as shown in the accompanying diagram.
The following optional features provide additional versatility to the unit:
- Serial link Options (RS-232C, RS-422A or others) for remote display, remote command panel, or computer interface are available.
- Additional parallel port in either BCD, or BINARY, or GRAY Code format with choice of sourcing, sinking or the TTL-type outputs.
Remote Display, 1890-D
This unit connects to the master 1890-R/1890-S unit via RS-422A or RS-232C serial port to provide remote indications if needed.