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M7350 PLS Module
Position Feedback
A PLC controlling a machine needs position feedback all the time. Two of the most common ways to provide position-feedback are an optical encoder with a counter card, or a resolver with a decoder. AVG Autotech offers a versatile resolver-based position feedback system. A resolver has several advantages over an optical encoder:
- Completely passive-electro-magnetic device
- Rugged & robust-tolerates higher mechanical shock & vibrations com-paredto fragile glass-disk encoders
- Wide temperature range-no conden-sationproblems at low temperature
- Immune to plant environment-oils, mists, dusts, etc.
- Absolute position compared to incremental encoders
Because of these advantages and the resolver's track record in automotive pressrooms, more stamping plants prefer a resolver-based system to optical encoder-based systems.
PLC Interface
The position feedback module uses a noise-immune ratiometric method to decode resolver signals. The decoded position is passed to the PLC through the backplane. The module may be programmed from the PLC. The module communicates with the PLC using Input & Output registers.
M7350-010 Single Resolver Model
The module works with AVG Autotech's RL100 or E7R single resolvers.Resolution is programmable from 20 to 1,024 counts-per-turn.
7350-020 Dual Resolver Model
The module works with AVG Autotech's dual (multiturn) resolver RL210 with 128:1 gear ratio. Resolution is up to 1,024 counts-per-turn, 128 turns maximum.
Programmable Offset
Both units feature a Programmable Offset which modifies the zero reference point, independent of the actual resolver position. This allows you to electronically align the resolver zero with the machine's zero-making installation easier.
Built-in Tachometer and Motion Detector
In the M7350-010 Module, the built-in tachometer and motion detector are updated over 68 times per second to provide fast, accurate indication and detection of rotary motion. The motion detector is programmed to energize the motion I/O status bit when the machine's RPM is between the low and high motion limits.
Broken Resolver Wire Detection
The M7350 Series ensures system integrity by detecting broken resolver cable wire. The Broken Wire I/O Status Bit is normally energized when the Module is operating normally and the resolver wire is intact. If the resolver is missing any signals, this information is passed to the PLC through its backplane, and the I/O Status Bit output is deenergized. |
