Trying to find a PLC
Trying to find a PLC
(OP)
Looking for a PLC with a operator interface (2 or 4 line LCD by 20 characters) and the ability to change about 3 or 4 parameters.
PLC must be able to supply voltage and recieve voltage signals to/from a resolver and make a calculation as to the position of the resolver (in degrees) based on the millivolt signals received from the resolver.
specs on the resolver: it needs for voltage input...750 to 850 mVAC. It supplies as output (x2, X & Y) 850 to -850 mVAC on each output.
the logic will be to recieve the mV inputs, calculate what the position is, then turn off/on digital outputs (to drive relays) based on the settings keyed in by the operator.
any ideas on PLC's that would do this. really trying to keep the cost down also.
thanks
PLC must be able to supply voltage and recieve voltage signals to/from a resolver and make a calculation as to the position of the resolver (in degrees) based on the millivolt signals received from the resolver.
specs on the resolver: it needs for voltage input...750 to 850 mVAC. It supplies as output (x2, X & Y) 850 to -850 mVAC on each output.
the logic will be to recieve the mV inputs, calculate what the position is, then turn off/on digital outputs (to drive relays) based on the settings keyed in by the operator.
any ideas on PLC's that would do this. really trying to keep the cost down also.
thanks





RE: Trying to find a PLC
RE: Trying to find a PLC
RE: Trying to find a PLC
RE: Trying to find a PLC
It depends on measurement increments you can afford.
Different brand PLC A/D converter modules may be of 8-10-12-14 bit resolution.
Respecting A/D convertion accuracy and linearity, and also the specific 1 bit error of digital systems, I would decrease the specified resolution by 2 bits.
The convertion time also may be a consideration.
Also, this voltage range most probably will require a signal amplifier.
RE: Trying to find a PLC
Automationdirect has a voltage input modules of 0-1.25 V input with 16 bit resolution. (F0-04THM)
They have interfaces as well.
search their web for full range.
www.automationdirect.com
RE: Trying to find a PLC
This device performs exactly the same function you are trying to emulate. I use the "ElectroCam" line of programmable limit switches. Why reinvent the wheel when you can buy it off the shelf?
best regards, PLCSAVVY
RE: Trying to find a PLC
best regards, PLCSAVVY