Urmet 1043 550A Guía De Uso Rápido página 12

Detection circuits
Use the holes at the bottom (wall side) to pass through the wires of the detection circuits and the various services.
Each loop-type detection circuit must be connected, respecting polarity, to the SLC LA and LB terminals near the respective circuit
module.
In the case of an open line, connect to terminals LA or LB (at most for two open lines connect max. 128 devices in total to terminals
LA and LB).
The detection circuit screening must be connected to the metal bottom of the control panel connected to electrical earth.
For loop lines, only one end must be earthed and the other left unconnected.
Device connection on loop line (Class A)
Device connection on open line (Class B)
DS1043-271 LBT21120
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