Do the DO and feedback DI of the cut-off valve have polarity? Is it necessary to pay attention to positive and negative connections in the terminal cabinet?
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Do the DO and feedback DI of the cut-off valve have polarity? Is it necessary to pay attention to positive and negative connections in the terminal cabinet?
The DO signal is primarily used to drive the on-site solenoid valves. These solenoid coils have positive and negative poles. If the DO signal is driven through a relay, the positive terminal is connected to the fuse terminal, while the negative terminal is either directly connected or connected to the switch terminal. In the case of DI signals, when the on-site contacts are of the dry-contact type, there are no positive or negative poles. When in use, the connection between the on-site side and the indoor side is severed, and it is checked whether there is any short circuit to ground, thereby preventing the fuse at the indoor positive terminal from burning out.
The DO terminal has no polarity, but attention should be paid to feedback; if it is a proximity switch, then polarity does exist