In both arms, the EN1 enable signal was copied and fed to the scalers as gates or vetos.
For the 1150s, the signal was used as a gate.
For the SiS modules, the signal was inverted (aka "notted") and sent in as a veto. Depending on the module, it was sent as either a NIM/LEMO or an ECL.
The inverted signal was also connected to the 560E module on the right, connected to the veto input.
This layout needs to be checked during and after a run to make sure the scaler outputs are working correctly.
That will be done shortly.