Hi to all,

I m new to Delta V. And I m using Ver-7.4.

to control of systems such as valves and motors why most uses the 'device control block' and not other blocks as' discrete output, for example that can takes a binary setpoint and writes it to a specified I/O channel to produce an
output signal?

 

Hi,

It depends on your application, on what you're trying to do I would say.

The Device Control block contains a state logic inside. It is indeed used a lot for discrete valves and motors.

For example, if you use a DC block and send the command open, you will drive the output of the DC block to open the valve. Then, you can configure the limit switches of the valve as inputs. Let's assume you have 2 limit switches, 1 for open and 1 for close. Well now, when you set the setpoint to open, the output send the open signal (1 for normally close valve and 0 for normally open) and the DC block waits for the correct feedback. You have parameters in the DC block that you can use to see when the valve is transitioning, what the valve is doing.

You can also configure interlock and permissive that you can wire to the DC block.

Hope this helps...