GE DS200DTBAG1A

DS200DTBAG1A is a Digital Contact Terminal Board manufactured by General Electric as part of the Mark V LM Series used in gas turbine control management systems. Q11, Q21, and Q51 are the locations of the Contact Input Termination Module (DTBA). The first 46 contact inputs in the same digital core are connected to TCDA through DTBA. To enable fail-safe contact input functionality, the inputs can be configured in the TCDA IO Configuration to invert the contact sense. JY receives 125 V dc power from the DTBA board. The TB2 terminal board allows the excitation voltage for contact inputs DTBA and DTBB terminal boards in the digital cores to be 125 V dc from core or 24 V dc from

core. Implementation of the desired contact input excitation option is done at the factory.

To provide a fuse isolated and current limited interrogation voltage for the contact inputs, the Mark V LM controller draws either 125 V dc or 24 V dc from the power distribution core. By cutting off the interrogation voltage, jumpers on the DTBA and DTBB terminal boards can be utilized to isolate field grounds.
They are connected in eight-contact input groupings. Changes to these jumpers should only be made when the turbine is not in operation. On the TCDA board, which is in Location 1 of the digital I/O core, each contact input is optically isolated.
The CPU on the TCDA board assigns a time stamp to each contact input within 1 millisecond of a status change. Whenever a contact input's state changes, the operator interface printer can record the time stamp if the input is chosen for logging. If the contact input circuit fails, diagnostic checks constantly run and sound an alert.