ABB ControlMaster CM10 User Manual page 107

ControlMaster CM10, CM30 and CM50
Universal process controllers,
The auto-manual station and analog backup station templates can be used in series or in parallel with the master output signal.
Parallel operation is achieved by using an external relay that is triggered by a relay on the ControlMaster, and selects the output
to be routed to the process. This setup allows uninterrupted control, even in the event of failure of either the master controller
or ControlMaster.
Master
Controller
PV
*External relay type is triple-pole, dual-throw.
Fig. 8.4 Parallel Connection
IM/CM/S–EN Rev. R
1 1 1
/ , / and / DIN
8 4 2
–
Output
AIN 2 +
+
AIN 1
External Relay*
NC
Control
Output
NC
NC
RLY1
8 Templates and Functionality
AIN 2 –
AO 1 +
AO 1 –
105