SE Controls OS2 Technical Information And Operating Instructions page 9

5.6 Slave Inputs
The slave inputs are designed to operate at 24VDC voltage levels. Connecting SBL and SBR to the 1BL and 1BR
outputs of an OS2 type 21 controller (see typical arrangement below) will cause the local controller to act as a
slave of the type 21 unit. A 2 core cable is required to make this connection.
In operation, the controller mimics the input demands as output demands but converts them from a
reversing 24VDC signal to the switching L1 and L2 AC signals required for 230VAC actuators.
5.7 Follower Inputs
The follower inputs are designed to operate at 230VAC voltage levels. Connecting E/N/L1/L2 between
master and slave controllers (see typical arrangement below) will cause the local controller to act as a
slave of the master unit. A 3 core + earth cable is required to make this connection
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