QSC Audio CM16a manual Operation- Bypass Switch Usage

Section 3: Operation- Bypass Switch Usage (continued)

NOTE! Before depressing the BYPASS switch, the gain (volume) settings on all amplifiers connected to the CM16a should be reduced to a safe level. This is advisable because the CM16a’s “Level Control” will be reset to 0 dB. (or NO attenuation) with the BYPASS. It is possible that the amplifiers could be at maximum output level if the amplifier gain controls are not turned down.

Location of BYPASS switch: The front panel has a small access hole on the right side about 12mm (1/2 inch) to the right from the PORT H LED. It is NOT LABELED to help prevent accidental use. This is the BYPASS mode switch. To return to normal operation, simply reestablish computer communications via the network or RS-232 and change the appropriate settings (or recall a previously saved Preset).

The way to put the CM16a into this first BYPASS mode (“virtual-wire mode”) is:

1- Turn the CM16a on and wait 5 to 10 seconds for the start-up LED sequence to finish.

2- Depress the BYPASS switch (use a paperclip or similar item) and keep it depressed for at least 5 seconds.

3- The two steps above must be completed within 60 seconds from

The second mode (“safe” mode)is used if the CM16a becomes inoperable (or behaves in completely unexpected ways) after

uploading a new application file (TFTP file transfer).

If the CM16a behaves in unexpected ways or is not responding to any communications after a new application file is uploaded to it, then it is likely that the new application file was corrupted during or after the data transfer. If sent a corrupted application file, the CM16a will not accept this file. The LED’s might even act in unexpected ways. If this occurs, there is a “backup” file in the CM16a that will enable you to communicate with it.

The way to put the CM16a into this second BYPASS mode (“safe mode”) is:

1- Turn off the power to the CM16a using the front panel power switch.

2- Depress the BYPASS switch (use a paperclip or similar item) and keep it depressed while turning the power on again. 3- The CM16a is now in “safe mode”.

You will now be able to re-establish communications with the CM16a using the RS-232 Input/Output port or the Telnet program in Windows NT. The following section describes the RS-232 and Telnet features. Once communications has been re-established, the file transfer can be tried again or the old application file used until the source of the data transfer problem can be found.

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