Hello, what's the difference between pressure module and signal module? The difference between pressure module and signal module lies in the different management hardware. The pressure module can be regarded as a monitoring module, which is mainly used for monitoring the state of equipment such as pressure switch, water flow indicator and signal valve. The signal module can be regarded as a control module, which controls the linkage equipment such as water pump, air supply outlet, fan, shutter door, power releaser and elevator through the 24V voltage or switching signal output by the module. Therefore, the difference between pressure module and signal module lies in the management hardware.