Industrial A/D Converter

[Bbarnett]

I'm looking for a standalone A/D converter like the one in the link but with 16-bit accuracy rather than 8-bit. Know of any product?

http://catalog.weidmueller.com/proc...3C?groupId=("group69976476519592")&page=Group

 

[shooter]

not seen yet 12 bits is available, but no 16 bit, what is application maybe i have solution with renesas micro.

 

[Geospark]

Quick Google search: SuperLogics 8017F 16-bit V, mV, mA 10 samples/sec

I'm sure there are others if you look.

G.

 

[Bbarnett]

Thanks for the replies.

I did come across that SuperLogics brand but it seems to output to an RS-485 network? I'm looking more for something that has 16 screw terminal outputs.

I'm thinking one way would be to have an analog input module, standalone PLC module, and a digital output module.. But this is very bulky and seems ridiculous to have just for one analog signal.

The signal I need converted is an analog spindle speed signal 0-10V. All of the analog inputs are being used but it has plenty of spare digital inputs available.

 

[rpoet]

The signal I need converted is an analog spindle speed signal 0-10V. All of the analog inputs are being used but it has plenty of spare digital inputs available.

How fast are your digital inputs? Can you use a quadrature encoder, and derive spindle speed from it? Can you add a high-speed input card to the existing controller?

Since you said "spindle speed," it sounds like a servo motor of some type. You could tap off the existing encoder lines if there is indeed an encoder.

Does the spindle drive have any communications ability? Can you communicate with it (RS485, RS232, Ethernet, etc...) to find out your spindle speed?


-rpoet

 

[Stephen Luft]

I am basically offering the same approach, an RS485 module interfaced to a PLC. The analog is 16 bit.

http://www.eternity-sales.com/tri-plc/peripherals.htm (I-7017)
http://www.eternity-sales.com/tri-plc/fmdseries.htm

If you have any questions, feel free to post, pm or email.

 

[shooter]

aha that explains a lot, can you use a relais o switch an analog channel that does not need a lot of speed like a temperature.
this way you can use a analog input double.
I do this a lot as analog input is expensive and a relais costing only 10 $.
I use 8 relais per analog input (just because it is still fast enough and my module has 8 outputs.
but i tested it with 200 relais on one analog still same result.
in your case with a volt signal you only need one spst contact, i use all four as i have Pt100.

 

[Fredlaroche]

@SHOOTER
But doesn't the switching of the relay result in a loop break detection? How do you mitigate this?

 

[shooter]

i first make a connection to next 1 the reading will be around -100 celsius. so no break detection.
this helps also very good for the hardware filter.
in temperature datalogging speed is about 1 log/hour.
all datarecorders even yokogawa work this way.