What’s the S1 Button For?


Your legacy Rexroth components may have an S1 button — a literal reset button. Some Rexroth electric motion control devices have the same button with an S2 label. Either way, it’s a chance to reset.

When should you use the reset button?

If you power down your equipment and change the parameters, the device will check when you power it back up to make sure that the new parameters match the stored parameters and that you’ve got the right motor type. You want the device to do this. After all, you may power down for other reasons, and you don’t want any accidental changes to go into effect.

But your Rexroth motion control will alert you to the mismatch of old and new parameters. If you’ve changed the parameters and you’re okay with the change, you hit the S1 button and your device accepts your changes. It’s basically the machine saying, “Hey, Boss, is this okay?” You hit the reset button and you’re saying, “Yes, I authorized this change.”

Except that really the conversation goes like this:


Less cordial, maybe, but it works.

Reset to default

The S1 button also allows you to overwrite any new settings and return to the original settings, initializing the device. This is a very good thing if that’s what you want to have happen. If not — say, you thought you wanted to go back to the original settings, but you didn’t realize that the settings you want are not the originals — it’s not a good thing.

You should therefore make sure that you have a trusted copy of the parameters before you make any changes. Any changes. At all.

After you’ve received an error message and corrected the error, the S1 button can be used as a reset button saying, “Okay, I’ve fixed the problem you told me about. Go ahead.”

If you need more help than this, give us a call at 479-422-0390. We specialize in Rexroth electric motion control, and we have seen it all over the decades we’ve worked with this machinery. We can help you. We have the nation’s largest inventory of emergency replacement units for Rexroth electric motion control systems, including legacy components. We can also arrange factory repair and reman.

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Call (479) 422-0390 for immediate assistance

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