When a sound and light alarm is connected to the GDS system, is it a DO signal or a DI?
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Guys, when a sound and light alarm is connected to the GDS system, is it a DO signal or a DI?
First, it’s necessary to distinguish between different types of I/O. Signals input into a system are called I, while those output from a system are called O. The audible and visual alarm is an external signal source for the GDS system; it serves as an input to the GDS. Therefore, when connected to the GDS system, the audible and visual alarm functions as a DI of the GDS system.
First, we need to figure out what DI and DO mean: OUTPUT and INPUT
To connect, it’s obviously DI, input
In and Out are relative; for example, for a sensor, sending out a signal is Out while receiving a signal is In. For a system, sending out a signal is Out and receiving a signal is In. When talking about I/O points, it is in relation to the system. Therefore, for the zone alarm controller, it is the system logic that sends out commands (to close); the field device receives these signals, so it’s a DO point. For the emergency stop button, external commands are sent, and the system receives those signals; thus, it’s a DI point.
If the alarm signal from the alarm device is output from the GDS to the on-site audible and visual alarm, then it is a DO signal
Determined relative to the alarm controller. It should be DO
Upon receiving a DO signal, the GDS system outputs the alarm status of toxic combustible gases via DO to the audible and visual alarm device, triggering audible and visual alarms.