eurotherm rs232

[new_ingenieur]

Bonjour,

J' aimerais acquérir la température de l' eurotherm 2704 avec une communication rs232 en utilisant des vi visa .

Sous MAX j' ai l' erreur 0xBFFF0072.*** la ressource est valide mais VISA ne peut pas actuellement y accéder**

Si quelqu'un a déjà utilisé l' eurotherm 2704 , je sollicite son aide.

Merci

[mikeporter]

What that  means is that there is another program that is already using the com port that you are connecting to your temperature controller. What orther programs do you have open that are using com ports?

Mike...

[new_ingenieur]

hello,

You are right. There was another program that used the com port. Thank  I have solve the problem
1 / But I have searched the NI website and there 's no drivers for 2704 only 24XX series
2 / In addition, when I send -> * IDN?n\ + query ,MAX does not send me the name of the device.

If I send -> IDN*? n\ + write, I have count bytes : 6 

Can you tell me why please?

[Dennis_Knutson]

The n\ an obvious mistake. The correct control code is \n and you need to confirm what the correct terminator actually is. You also need to confirm that the device actually supports the *IDN? query. Did you find it listed in the manual?

[new_ingenieur]

HI

It is my first communication with labview rs232.
I thought IDN? \ n is a universal command to all devices. I will look for instructions in the manual and if I have problems  I'd share with you.

thank's

[Dennis_Knutson]

No, it's not universal at all. It is a requirement for GPIB instruments.

[mikeporter]

The communications protocol that Eurotherm uses is modbus so all you need are modbus drivers. The model of the controller is essentially immaterial -- for this aspect at least. You can download modbus drivers from several places.

The other thing to remember is that the protocol is the same regardless of how you communicate with the controller. For example, some controllers have Ethernet interfaces, but use the same modbus protocol.

Mike...

[new_ingenieur]

OK .. But for the 2704 eurotherm what kind of order should I send to MAX to check if the communication is established

[Dennis_Knutson]

I don't know since I don't have the manual or the instrument itself. Any command that returns something.

[new_ingenieur]

Ok thanks I'll look in the manual or ask the manufacturer