Setting upper and lower limits on values sent to an analog output point so they do not go above or below a specific limit. For example, if you are using a 0-10 VDC output module, but the device attached to one of its points can handle a maximum of only 5 VDC, you can set an upper clamp of 5VDC for that point. Opto 22 SNAP PAC brains have the ability to clamp analog outputs.