QSC Audio CM16a manual Operation- Bypass Modes and Switch Location

Section 3: Operation- Bypass Modes and Switch Location

NOTE! Before depressing the BYPASS switch, the gain settings on all amplifiers connected to the CM16a must be reduced to a safe level. This is because the CM16a’s “Level Control” will be reset to 0 dB with the BYPASS. Amplifiers could be at maximum output level if the amplifier gain controls are not turned down.

BYPASS MODE #1 (“virtual-wire”mode): Use this mode if you need the CM16a to behave as a virtual wire. This BYPASS mode routes all audio straight through with 1Vrms input sensitivity, PAGE input disabled, MUTE disabled, 0 dB level, and normal polarity. All amplifier control states are set to “on”. Audio passes through the CM16a regardless of network/computer issues.

HOW TO put the CM16a into BYPASS MODE #1:

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 power-up. If you miss the timing, just power-down and power-up again and repeat steps 1 & 2.

BYPASS MODE #2 (SAFE MODE): Use if the CM16a becomes inoperable (or behaves in completely unexpected ways)

after uploading a new application file (TFTP file transfer).

If the CM16a operates in an unexpected way or is not responding to any communications after a new application file is uploaded to it, it is likely the file was corrupted during transfer. If this occurs, there is a “backup” program in the CM16a that will enable you to communicate with it.

HOW TO put the CM16a into BYPASS MODE #2:

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 may release the BYPASS switch.

You will now be able to re-establish Ethernet communications with the CM16a. Once communication 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. In safe mode, all connected amplifiers are forced to the standby state, and all audio paths are muted. Also, no QSControl communication is possible, only TFTP or Telnet, or RS-232.

Location of BYPASS switch: The front panel has a small access hole on the right side about 12mm (1/2”) 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). After completeion of a successful TFTP file transfer/code re-program cyclefrom the safe mode, the CM16a will automatically restart in the normal mode of opera- tion.

26