Analog input

Jasek

Hello everybody

 

Im working with RS, and i have used some digital inputs to simulate the process.

 

But now i have to change this digital inputs to analog ones.

 

My question is:  If I configure the analog input variable parameters ( of the robot, with the robot controller) Physical Max, Physical min, logic max and logic min, the robot controller will convert the analog values that it receives to the others i need?

 

For example, it receives "mA", can the robot controller convert it to a "distance" automatically?

 

Or should I make the change in the rapid programming  y-y1=m(x-x1) ?

 

Thank you very much in advance.

 

PS. I dont know if this is the place to put this topic, if not.. sorry

kioog

yes indeed, here is an example for a 4-20mA sensor, it reads an analogue signal from a distance sensor and it will result on the robot in  a distance

 

     -Name "DI11_AI_Laser" -SignalType "AI" -Unit "Festo_GRIP"
      -SignalLabel "Laser Festo unit" -UnitMap "0-15" -Default 100
      -EncType "UNSIGNED" -MaxLog 500 -MaxPhys 4096 -MaxPhysLimit 4096
      -MaxBitVal 4096 -MinLog 100

 

if the sensor sends analogue output 4mA=100mm and 20mA=500mm.

the robot scales the analogue input between 100mm and 500mm.

 

4096 is the value i get for 20mA, it depends on the bit resolution of your sensor

Jasek

 Thank you very much for answer too early, im a little bit in a hurry heheh.

 

I only have the data sheet of the sensor, and there only appears the next about Resolution : < 0,2mm.

 

But in the user manual that i have of the robot, it doesnt appear the next fields : MaxPhysLimit, MaxBitVal.... just the four one I wrote in the first post :S. The robot is an IRB 1400.

 

And yes the sensor give me:   4mA=100mm and 20mA=300mm 

 

Jasek

Hello, two more little newbie question.

 

If i want to connect the sensor to there robot, I have to do it through the robot controller isnt it? hehe

 

and, When the laser doesnt detect anything on its range, sends to the robot 0 mA, true?

 

Thanksss in advance, im starting to practice with industrial robots.

kioog

this depends on the laser you use i think, on mine when i don't detect anything it gives me 500mm, if i go closer than 100mm it always gives me 100mm.

i am using a IRC5 controller, maybe you use S4C+?

 

about the resolution,i mean it is the bit width the laser sends out the data.

if you use a 12 bit laser, the maximum value you get is= 4095

 

you can try to also define a group input of you laser bits and see what value you get and enter these in Physical Max, Physical min

the logic max and logic min values are the limits for the calculated values you want to use in your program, the distance in this case

 

you have to connect your sensor to an analogue input card, those are normally not standard delivered with the robot.

Or you can use wago modules with devicenet and add an analogue input module, on IRC5 you can use any model, but on S4C+ you may have to use a specific model if I remember well.

Jasek

Ok thank you peter

I dont want to disturb you too much. But i have a new problem.

 

Anyone knows how can i solve the next problem?

 

I want to move the robot linear with "SearchL", but this command needs an digital input, and the laser i think only has 1 analog output. is it possible to connect it to an analog input and to a digital one at the same time? the connection type is 5pin,M12., i dont think so

 

Well the operation needed is the next: i have to move the robot linear, and when the laser detects an object, stop the robot movement, and read the distance.

They gave me a tip, to use the SearchL, in order to avoid the accelerations and decelerations of the robot, and make a soft movement.

 

Thanks if anybody can help me

dhyan

Hello, I think you need to use ADC. Based on my experiences, I connect all of my analog inputs to ADC, then ADC send signal to PLC and PLC will send it to Robot Controller. PLC is stable and more cheaper than any robot device. In the future I will implement Profibus to create the high speed data communication.
I hope my suggestion will give you inspiration.
BR,
Dhyan
Indonesia

kioog

Jasek,

 

this is a thought about how you can maybe manage your problem, i never used it, but it may be possible i think

 

you can make a interrupt to your analogue input with IsignalAI?

in this trap you set a virtual output that you link to a virtual input with cross connection

 

and use this virtual input in your searchL

 

Hope this helps you.

Hugo Mendes

I tried to use ISignalAI but i get a unknown error. I created an analog signal with 9 bits. Maybe i got to create a "pure" analog input? The problem is that i don't know  how to do it.

Hugo Mendes2011-02-01 10:01:23

Hugo Mendes

My signal is analogic input

unit mapping: 0-15

encoding: two complement

max logic value:180

max physical val:10

max physical val lim: 10

max bit value: 32767

min logical val: -180

min physical val:-10

min physical val lim: -10

min bit val: -32767

assigned to unit: unidade

 

type of unit: d355A

connected to bus: DeviceNet1

DeviceNet address:63

 

Still can't fix the problem...