CHARLESTON — Federal agencies in South Carolina and across the nation are conducting the first national test of the Emergency Alert System.

The test is scheduled for Wednesday at 2 p.m. and will sound over radio and television outlets including cable and satellite audio and video.

The test is being conducted by the Federal Emergency Management Agency, the Federal Communications Commission and the National Weather Service. The test may be last a minute in length.

The agencies are asking the public not to call 911 with questions about the test. That could prevent actual emergency 911 calls from getting through.