Just to show parameters, really needs PLCs?

Hi,

i have a set of only 12 parameters ( 5 voltages signals, 1 freq, 5 resistances, and 1 signal through RS232 ).

I wanna show these parameters on a screen.
Can suggest a configuration for me? wat cards do i need to buy etc.

issit that, i must use plc to achieve this purpose? coz, sounds a bit wasteful on the PLC, coz it only take data, and pass it to the monitor...

You don't need a PLC indeed. Just google for "data acquisition ethernet" and you'll find thousands of possible solutions. Without more information, there is however no way for us to tell you exactly what you need in this situation.

Kind regards,

But another part of the question might be - what else to you intend to do with those signals? Are you just going to monitor them? Or do you ever intend to use them as controls for something else? If you plan on ever controlling with them, you might as well go ahead and get them into a PLC.

thsnk for reply...
let say, i just wanna monitor the data (1 signal from each of the 12 devices) on the screen. Just monitor, no control at all. And if possible, data log as well. what kind of setup should i approach to?

the 12 signals that i have, is connected to analog dial, which show the values as well, but i am looking for a way to display the parameters on a secondary display (LCD screen).

The ethernet acquisition that u mentioned, must i look for converters or transducer? because the 12 signals came in to my "station" as different type of signals as u can see (for eg, Voltages, RS232 signals)

by the way... for the temperature signals, i just configure the analog card as PT100, right ? if i am using a siemen plc..

considering for future upgrades, i am considering to use a plc to display the data on the screen. Now my problem is...

i am using a Siemens VDO temperature sensors thermistor 92-027-004. the temp vs ohms table that the supplier gave me doesnt look like a PT100 standard...

how do i know how should i configure my analog card ? any idea?

sorry if i asked stupid question~

Analog cards come in all flavors.

You can only connect an RTD directly to the card if it is an analog card specific with RTD inputs.

If you have a 4-20mA/0-10V card you'll need a transmitter to go along with it which will convert the RTD resistance to a 4-20 mA signal. Of course those come in all flavors!

EDIT: Here is a page full of them http://www.phoenixcontact.com/signal-level-matching/31244_14914.htm

thsnk ~ for the infor...

wanna know, is there an analog card that siemens offer that can take 0 VDC to 20VDC? wat i found mostly are +/- 10VDC...

skygon said:

thsnk ~ for the infor...

wanna know, is there an analog card that siemens offer that can take 0 VDC to 20VDC? wat i found mostly are +/- 10VDC...

Click to expand...

No. I doubt if you would find it anywhere either. Standard analog voltage signals in automation are 0..+10Vdc, -10Vdc..+10Vdc, 0..+5Vdc and +1..+5Vdc. Most used standards are -10Vdc to +10 Vdc and +4mA to +20mA. Besides that, you'll find analog cards for different temperature sensors, such as PT100, PT1000 and different thermocouples.

If you need other signals, then you have to find or make an adaptor. For 0 to +20Vdc I would suggest to use a resistor and form a voltage divider with the input impedance of the -10Vdc..+10Vdc card. It's simple, reliable and cheap.

Kind regards,

Hi ~

I have a device from Siemens VDO ( a dial gauge, which connects to a thermistor ) that gives me an analog display of a certain fuel temperature. The only infor i was given was a table of ohms vs degree celcius.

I can see that the table is not in PT100, it is in non-linear method.

my questions is, can i just directly tap the signal from the same thermistor (which direct connect to the dial) to my PLC analog cards?
Coz, i assume the signal tap from the thermistor gives me resistance values? i haven seen the actually thing yet on site, i am preparing myself by reading the documents only.

if not, must i buy a convert that converts ohms to 4-20mA, then to the PLC analog card?