Gpo Tally Outputs - evertz 5700ACO User Manual

position and DIP switch 8 is in the off position, and in automatic mode, only 1 change will be allowed if
they occur within 0.5 seconds. When DIP switch 8 is in the On position, and in automatic mode, only 2
changes will be allowed if they occur within 0.5 seconds. After this, the LEDs beside the switches will
flash. The leftmost toggle switch for the manual/auto mode will re-enable the 5700ACO. This is
provided to prevent back and forth toggling if an output is shorted out.
NOTE: When DIP switch 8 is ON, the 5700ACO will not change over after a quick

change has happened. User input is needed to allow automatic changes to
happen again. It is important to promptly fix the offending input, and re-enable
the 5700ACO to ensure correct automatic protection.
3.4.

GPO TALLY OUTPUTS

There are two general purpose outputs that can be used to signal alarm conditions to the user. These
outputs are driven by normally closed relays inside the 5700ACO. When the relay is energized (active),
the output will be pulled to +5 volts by a 10 K ohm pull-up. When the relay is de-energized (normal) the
relay contact will connect the output to ground. See Figure 2-4 for a schematic of the GPO output
circuitry.
GPO1 is used to indicate whether Master A or Master B is currently selected. It will be low when
Master A is selected and high when Master B is selected.
GPO2 is used to indicate whether the Master A and Master B inputs are identical and the power
supplies are functioning correctly or not. It will be high when the inputs are identical and the power
supplies are good, and will be low when the inputs are not identical, or one or both of the power
supplies is not functioning correctly.
The default condition of the 5700ACO outputs when there is no power applied is that the Master that
was last active will be selected, and will be indicated by the GPO1 relay. GPO2 will be high impedance.
Revision 1.0
5700ACO
Automatic Changeover
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