Suppose you have an application where you need to control the drive run stop remotely
from a control room using a digital input.
But, when you are at the drive, you want to use the drives built-in HMI keypad to control
run stop and you don’t want the control room to start the drive while you are working
on it.
I would typically refer to this as my remote control and this as my local control, and then
I would add a switch to flip between the two modes.
So really, remote and local are just two different drive configurations that you can switch between.
We could have called them Drive Configuration 1 and Drive Configuration 2, but since most
folks use them in a remote local setup like this, they are generically called Remote and
Local modes.
The truth is, I could store this configuration in Remote mode and this configuration
in the Local mode if I wanted to.
Maybe at your factory, the drives are considered to be remote from the control room, so the digital
run stop is considered the local control and the drive’s HMI is the remote control.
The drive really doesn’t care.
It all depends on your application and your point of view and how you want to refer to
the two different configurations.
Remote is one configuration, local is another.
How you configure them is up to you.
In each one you can configure Run/Stop, the speed control, Forward and Reverse, and Jog.
Let’s do the above example where we control the run stop remotely using a digital
input and locally via the drive’s HMI keypad.
We’ll control the speed of the drive in both configurations from the drive’s HMI
keypad.
Both configurations will set forward and reverse to forward only and we won’t use any jog.
Now, before starting, let’s reset the drive to factory default so we are starting in the same
place.
I went ahead and entered these motor and ramp parameters for my setup.
I’m using the free WPS software and this optional USB comm module for this video to
make it easier for you to see what I am doing.
You can do everything we are going to do here right from the drive’s built-in HMI if you prefer to
do it that way.
OK, for local mode we want the keypad to control run stop.
So, I’ll search on Local and we see that the local run stop defaults to the HMI keypad,
so we don’t need to do anything there.
Looks like local mode also defaults to having the speed controlled by the keypad, forward
reverse defaults to always forward only and JOG is not used.
Those also happen to be exactly what we want to do.
Again, even though we are calling it local mode, you can control any of these from any
of the remote comm's, digital I/O, etc.
Great,
Local is done so let’s search on Remote and set that up.
Looks like run stop defaults to being controlled by a digital input which is exactly what we
want.
So that’s fine.
The drive speed defaults to analog input control. Let’s change that so we can control
the speed from the HMI keypad when in remote mode.
Forward and reverse defaults to controlled by a digital input. We want that to be forced
to always forward.
And jog also defaults to being controlled by digital input.
We aren’t using it in this example, so we'll select not used.
Ok, we’ve configured the drive operation for both local and remote modes.
All that is left, is to switch between them.
Parameter 220 controls that and it looks like it defaults to always local.
We’re going to have a switch that controls the mode, so let’s change local remote select
to being controlled by a digital input.
If we search on digital input, we see that digital input 4 isn’t being used, so let’s
have that be our local remote selector.
I’ve wired these two switches to the drive like this.
So, when I am in LOCAL mode, I can start and stop the drive using the drive’s HMI keypad.
But not the switch.
And when I am in remote mode, I can control the drive from the switch, but not the HMI.
Perfect.
Also, the drive’s HMI/Keypad controls the speed in both remote and local modes.
Exactly what we asked for.
Here is a summary of the parameters we used in this video.
I’ll include that list in the videos description below, so you can cut and paste it into your
own document.
Click here to learn more about the CFW300 series of variable frequency drives.
Click here to learn about AutomationDirect’s free support options and click here to subscribe
to our YouTube channel so you will be notified when we publish new videos.